Question bank

Chapter-1   Kinetic Molecular Theory of Matter
Q-1 Answer the following questions.

(1) Explain how water spilled on the floor disappears into the air. Name the phenomenon that accounts for it.

(2) Frost forms when particles of water vapour come in contact with a very cold surface. Name and explain this process and give an example of where you might observe it.

(3) Explain in the light of the Kinetic Molecular Theory the following phenomena: (i) Boiling (ii) Melting (iii) Sublimation

(4) How does the Kinetic Molecular Theory of matter explain the existence of: (i) Solids (ii) Liquids (iii) Gases

(5) Which of the following provide evidence that liquids and gases consist of moving molecules: (i) Diffusion (ii) Evaporation (iii) Difficulty of compressing liquids

(6) What is diffusion?

(7) Explain the following terms: (i) Matter (ii) Atom (iii) Molecule (iv) Element

Q-2 Answer the following questions.
(1) What is meant by Brownian movement? What does it prove?
(2) State the characteristics of the Brownian movement.
(3) Why does Brownian movement not occur in solids?
Q-3 State whether the following statements are true or false.
(a) The kinetic energy of the molecules of a gas increases when the temperature of the gas increases.
(b) Molecules in the vapour state of the substance are smaller than those in the liquid state.
(c) For a given substance the molecules in the vapour state are further apart than in the liquid state.
(d) Molecular motion of molecules takes place at all temperature.
(e) Intermolecular spaces in solids are more than in gases.
(f) Rate of evaporation increases with increase in temperature.
(g) Solids do not diffuse due to lack of intermolecular spaces.
(h) Evaporation can occur at all temperatures.
(i) The change of liquid into solid is called condensation.
(j) Ammonium chloride sublimes on heating.
Q-4 Fill in the blanks:
(a) ________ account for the pressure exerted by gas.
(b) The difference in the three states of matter is based on the _______ of their atoms and molecules.
(c) Brownian motion increases with the ________ in the density of the medium.

(d) If the temperature ________ , Brownian movement also _______

(e) Evaporation causes _______
(f) ________ sublimes at room temperature.
(g) When a solid is heated, its internal kinetic energy _______
(h) ________ is a rapid process and takes place at a fixed temperature.
(i) The heat needed to change a solid into a liquid at the same temperature is called latent heat of ______________
(j) The irregular motion of suspended particles in a liquid is called _______ motion.
Multiple Choice Questions
Q-1 The state in which the molecules can move freely within the boundary of the substance is:

(i)

Solid

(ii)

Liquid

(iii)

Gas

(iv)

Plasma
Q-2 The Brownian motion increases with the:

(i)

Increase in density of the medium

(ii)

Decrease in temperature

(iii)

Increase in size of particles

(iv)

Decrease in size of particles
Q-3 Mercury is a _______ at room temperature.

(i)

Solid

(ii)

Liquid

(iii)

Gas

(iv)

None of these
Q-4 The change from the solid state to liquid state on heating at a fixed temperature is called:

(i)

Melting

(ii)

Sublimation

(iii)

Freezing

(iv)

Condensation
Q-5 The substance that sublimates is:

(i)

Wax

(ii)

Ice

(iii)

Pure iron

(iv)

Iodine
Q-6 The state in which the intermolecular force is the least is:

(i)

Liquid

(ii)

Solid

(iii)

Gas

(iv)

Plasma
Q-7 Evaporation takes place at:

(i)

Fixed temperature

(ii)

Fixed pressure

(iii)

Any temperature

(iv)

None of these
Q-8 Gases have:

(i)

Fixed shape and volume

(ii)

Variable shape and volume

(iii)

Variable shape but fixed volume

(iv)

Fixed shape but variable volume
Q-9 The three states of matter depend on:

(i)

Temperature

(ii)

Force

(iii)

Potential energy

(iv)

Volume
Q-10 The random motion of smoke or gas particles in air is called ________ motion.

(i)

Bruneian

(ii)

Blackian

(iii)

Randomium

(iv)

Brownian
Q-11 The continuous motion of particles in solids, liquids and gases is observed as:

(i)

Potential model of atoms

(ii)

Kinetic model of matter

(iii)

Kinetic model of atoms

(iv)

Potential model of matter
Q-12 Intermolecular forces can be defined as force between:

(i)

Two solids

(ii)

Two substances

(iii)

Two atoms or molecules

(iv)

Liquids and gases
Q-13 Matter consists of tiny particles called:

(i)

Molecules

(ii)

Atoms

(iii)

Ions

(iv)

Elements
Q-14 Solids are:

(i)

Compressible

(ii)

Diffusable

(iii)

Incompressible

(iv)

None of these
Q-15 

During a change of state, the KE of molecules _______ and PE ______

(i)

Increases, decreases

(ii)

Decreases, increases

(iii)

Remains same, changes

(iv)

Remains same, remains same
Chapter-2   Measurement of Volume and Density
Q-1 What is density? State the unit of density in:
(a) CGS system
(b) SI unit
Q-2 Convert the following as instructed:
(a) 13.6 g/cm3 into SI unit
(b) 1 g/cm3 into SI unit
(c) 2700 kg/m3 into CGS system
(d) 800 kg/m3 into CGS system
Q-3 Answer the following questions.
(a) Why do some substances have densities higher than others?
(b) When a body is floating, it experiences two forces. Name the two forces.
(c) What is upthrust?
(d) A body weighs 100 gf in air and 82 gf in water. What is the upthrust acting on the body?
(e) Find the density and relative density of the body.
(f) While floating, is the weight of the body greater than, equal to or lesser than the upthrust?
(g) The mass of a block made of certain material is 1.35 kg and its volume is 1.5 x 10-3 m3 . (i) Find the density of the block. (ii) Will this block float or sink in water? Why?
(h) A given body A weighs 25 g in air, 20 g in water and 22.5 g in liquid B. Calculate the density of the body A and that of the liquid B.
(i) The relative density of silver is 10.8. What is the density of silver in SI unit?
(j) A metal cube of side 5 cm and density 7 .9 g/cm3 is suspended by a thread and is immersed in the liquid of density 1100 kg/m3 • (i) Calculate the mass of the cube. (ii) Calculate the upthrust acting on it when it is immersed in the liquid.
(k) A piece of iron of density 7.8 g/cm3 and volume 10-4 m3 is totally immersed in water. Find: (i) Weight of iron piece in air. (ii) Upthrust (iii) Its apparent weight in water. (density of water = 1 000 kg/m3 ).
Q-4 Answer the following questions.
(a) What is relative density?
(b) Why does relative density have no units?
(c) A solid weighs 32 gf in air and 28.8 gf in water. Find the volume and relative density of the solid.
Q-5 State whether the following statements are true or false:
(a) Upthrust = Loss in weight of body in the fluid.
(b) Upthrust = Weight of fluid displaced.
(c) Upthrust = Weight of body in air - weight of body in fluid.
(d) Upthrust = Apparent loss in weight of the body.
(e) Upthrust is a force which opposes the force of gravity.
Multiple Choice Questions
Q-1 The density of an object is:

(i)

Mass divided by volume

(ii)

Volume divided by mass

(iii)

Mass multiplied by volume

(iv)

None of these
Q-2 If two objects have the same mass but different volumes:

(i)

They must have the same density

(ii)

The object with greater volume has higher density

(iii)

The object with greater volume has lower density

(iv)

None of the above
Q-3 The density of water is 1 g/cm3 • This means that the mass of 100 cm3 of water will be:

(i)

1 g

(ii)

50 g

(iii)

1000 g

(iv)

100 g
Q-4 Density is a characteristic property of a substance. This means that the density of water:

(i)

Changes if the volume changes

(ii)

Stays the same regardless of volume

(iii)

Is greater if mass of water is increased

(iv)

Is less if mass of water is decreased
Q-5 To find the mass of the water in a graduated cylinder:

(i)

Subtract the mass of water from the combined mass of the cylinder and water

(ii)

Add mass of water to mass of cylinder

(iii)

Subtract mass of cylinder from combined mass of cylinder and water.

(iv)

Divide the combined mass of water and cylinder by 2
Q-6 An object will remain suspended just below the surface in a liquid if it is

(i)

Denser than the liquid

(ii)

Less dense than the liquid

(iii)

As dense as the liquid

(iv)

Both band care correct
Q-7 The density of hot and cold water are different mainly because:

(i)

The molecules in hot water are closer

(ii)

Hot water has more molecules

(iii)

Molecules in hot water are further apart

(iv)

Hot water has less molecules
Q-8 Wood floats on water. If mass of unit volume of wood and water are compared:

(i)

Water has greater mass

(ii)

Water has less mass

(iii)

Wood and water have the same mass

(iv)

Wood has a greater mass
Q-9 The density of water is ___________ at ______ °C.

(i)

Minimum, 4

(ii)

Maximum, 0

(iii)

1 g/cm3 , 0

(iv)

1 000kg/m3 , 4
Q-10 Relative density of mercury is 13.6. Its density is _____ in CGS unit and ____ in SI unit.

(i)

13600 g/cm3 , 13.6 kg/m3

(ii)

13.6 g/cm3 , 13.6 kg/m3

(iii)

13.6 g/cm3 , 13600 kg/m3

(iv)

13.6, 13600
Q-11 A paper clip has mass 9 g and a volume of 3 cm3 • Its density is:

(i)

3 g/cm3

(ii)

0.3 g/cm3

(iii)

27 g/cm3

(iv)

9 g/cm3
Q-12 The water level in a graduated cylinder rises from 50 cm3 to 65 cm3 when an object is suspended in it. If the mass of the object is 100 g, its density is approximately:

(i)

6.67 g/cm3

(ii)

10.0 g/cm3

(iii)

4.0 g/cm3

(iv)

5.0 g/cm3
Q-13 The device used to measure the mass of an object is a

(i)

Graduated cylinder

(ii)

Ruler

(iii)

Beam balance

(iv)

Spring balance
Q-14 

A pebble has a mass of 14 g and volume 2cm3 • Its density is and relative density is ______

(i)

7 ml; 7

(ii)

7; 7 g/cm3

(iii)

7 g/cm3 ; 7

(iv)

28 g/cm3 ; 28
Chapter-3   Force and Pressure
Q-1 Answer the following questions.
(a) What is meant by force? State and define the SI unit of force.
(b) A force of 10 dyne with moment arm 100 cm long rotates a body in the clockwise direction. Find its torque. Draw the corresponding diagram.
(c) Which produces a greater moment: A force of 10 N with an arm of 3 m, or a force of 8N with an arm of 4 m?
(d) The moment of a force of 10 N about a point O is 5 Nm. Calculate the distances of O from the force.
(e) The figure shows two opposite forces X and Y of magnitude 3N and 5N respectively acting at the points P and Q which are at a separation of 400 cm . Calculate the resultant moments of the two forces about the point O which is situated equidistant from the two forces.
Q-2 Give two examples of force that:
(a) Causes a body to move.
(b) Brings about a change in the dimensions of a body.
Q-3 Answer the following questions.
(a) What is meant by moment of force? How is it measured?
(b) What are the two types of moments? Illustrate with diagrams.
(c) State three ways the turning effect of force can be increased.
Q-4 Explain
(a) A long spanner is used to loosen a tight nut.
(b) Torque is a vector quantity.
Q-5 State the effect of force in each of the following and identify the agent supplying the force:
(a) A bowler bowls a ball at a batsman.
(b) The batsman hits the ball which is deflected by a fence on the field and rolls on the ground.
(c) A fielder picks up the ball and throws it back to the bowler.
Q-6 Fill in the blanks:

(a) This turning effect of force depends upon two factors - the of the _________ force and the __________ arm.

(b) _____________ is used when there is an axle or pivot to be turned around.
(c) ___________ tends to be used in non-rotational situations such as a beam.

(d) Unit of torque in CGS units is ________

(c) ___________ tends to be used in non-rotational situations such as a beam.
Q-7 Answer the following questions.
(a) What is pressure?
(b) How can pressure acting on a body be reduced?
(c) How can pressure acting on a body be increased?
Q-8 Explain why:
(a) Camels have broad flat feet.
(b) Buildings have a wide foundation.
(c) Knives and other cutting tools have a sharp edge.
Q-9 Calculate the pressure acting on a body from the information given below:
(a) Force 80 dyne , Area 10 cm2 , Pressure = ___________ dyne/cm2
(b) Force 80 N , Area 100 cm2 , Pressure = _____________ newton/cm2
(c) Force 80 N , Area 10 m2 , Pressure = ___________ newton/m2
(d) Force 800 dyne , Area 10 m2 , Pressure = _____________ , ____________
Q-10 A book weighing 1200 dyne has length = 20 cm, breadth = 12 cm, thickness = 4 cm. Calculate the pressure the book exerts on the table surface:
(a) When it is made to stand on its edge.
(b) When it is made to lie flat on the table.
Q-11 Three bricks are kept on a table in three different positions A, Band C as shown below. The pressure exerted by the brick will be:
(a) Maximum in position A.
(b) Maximum in position C.
(c) Maximum in position B.
(d) Equal in all.
Q-12 A container is filled with water as shown in the diagram. Which statement is true about the pressure of water?
(a) Pressure at A > Pressure at B > Pressure at C.
(b) Pressure at all three points A, B, and C is the same.
(c) Pressure at C > Pressure at B > Pressure at A.
(d) Pressure at C > Pressure at A > Pressure at B.
Q-13 An experiment was performed as described below:
(a) Water was boiled in a firm thin tin container.
(b) After much of the air was driven out, the cap was replaced.
(c) On cooling the can, it was found that it crushed easily.
Q-14 With respect to the experiment described, account for the following:
(a) At the start of the experiment, the shape of the container is maintained.
(b) Even as the water boils and forms steam, the shape of the container is maintained.
(c) The cap of the container is replaced.
(d) On cooling the can, it crushes easily.
(e) What does this experiment demonstrate?
Q-15 Vessels A, Band Care filled to the same height with water.

(a) The force at the bottom of A is _____________ the weight of the water. (i) greater than (ii) less than (iii) equal to

(b) The force at the bottom of B is ____________ the weight of the water. (i) greater than (ii) less than (iii) equal to

(c) The force at the bottom of C ____________ the weight of the water. (i) greater than (ii) less than (iii) equal to

(d) The pressures on the bottom of A, B and C are ____________ (i) not comparable (ii) the same (iii) different

(e) Pressure depends on ____________ (i) area and density (ii) area, height and density (iii) area and height
(f) Force on a container depends on _______ (i) area and length (ii) area and density (iii) area, height and density
Q-16 State whether the following statements are true or false:
(a) A liquid seeks its own level.
(b) Pressure at a point in a liquid is the same at all points in the same horizontal plane.
(c) For a given area, the pressure acting on it is always greater than the thrust on it.
(d) Pressure increases with increase in altitude.
(e) In the mercury barometer, the vertical height of the mercury column is independent of the shape and size of the tube.
(f) At constant temperature, when the pressure on a gas is increased, the density of the gas increases proportionately.
(g) An increase in pressure lowers the boiling point of a liquid.
(h) Winds blow from a region of low pressure to a region of high pressure.
(i) Pressure at a point inside a liquid at rest is equal in all directions.
(j) Pressure acting on a body varies inversely as the area in contact.
Q-17 The base of a cylindrical vessel measures 300 cm2 • Water is poured into it upto a depth of 6 cm. Calculate:
(a) The pressure of water on the base in pascal (Pa).

(b) Thrust of water on the base. (Take g = 10ms-2 and density of water as 1000 kg/m3)

Q-18 A dam is constructed on a river at a place where a 30 m deep lake is formed. Calculate the pressure of water on the dam:

(a) at its bottom

(b) at a depth of 20 m
Multiple Choice Questions
Q-1 The force exerted by the Earth to pull objects towards it is:

(i)

Electrostatic force

(ii)

Gravitational force

(iii)

Magnetic force

(iv)

Buoyant force
Q-2 The absolute unit of force is:

(i)

newton

(ii)

pascal

(iii)

watt

(iv)

joule
Q-3 The strength of force is expressed by its:

(i)

Mass

(ii)

Weight

(iii)

Magnitude

(iv)

None of these
Q-4 The tendency of a force to turn a body is called:

(i)

Torque

(ii)

Pressure

(iii)

Moment of force

(iv)

Both a and c
Q-5 The SI unit of moment is:

(i)

dyne cm

(ii)

newton-metre

(iii)

newton

(iv)

joule
Q-6 Anticlockwise moment of force is taken as:

(i)

Negative

(ii)

Positive

(iii)

Both a and b

(iv)

None of these
Q-7 Force and torque are:

(i)

Scalar quantities

(ii)

Force is a vector quantity and torque is a scalar quantity

(iii)

Both are vector quantities

(iv)

Force is a scalar quantity and torque is a vector quantity
Q-8 Which produces a greater turning force?

(i)

A force of 50N and moment arm 3 m

(ii)

A force of 30N and moment arm 8 m

(iii)

A force of 6N and moment arm 6 m

(iv)

A force of 1 5N and moment arm 4 m
Q-9 When a given force is applied on a larger surface area of contact, the pressure exerted by it:

(i)

Increases

(ii)

Decreases

(iii)

Is unchanged

(iv)

None of these
Q-10 The instrument used to measure atmospheric pressure is:

(i)

Thermometer

(ii)

Barometer

(iii)

Manometer

(iv)

Ammeter
Q-11 We are not crushed under the weight of air because:

(i)

Air has no weight

(ii)

Our internal body pressure due to fluids balances the atmospheric pressure

(iii)

Atmospheric pressure is negligible

(iv)

None of the above
Q-12 1 kilogram weight is equal to:

(i)

98N

(ii)

0.98N

(iii)

9.8N

(iv)

0.098N
Q-13 Atmospheric pressure at higher altitudes is:

(i)

More

(ii)

Less

(iii)

Same

(iv)

None of these
Q-14 The pressure exerted by a liquid:

(i)

Decreases with depth

(ii)

Does not change with depth

(iii)

Is different in different directions

(iv)

Increases with depth
Q-15 The pressure exerted by the air around us is called:

(i)

Thrust

(ii)

Upthrust

(iii)

Atmospheric pressure

(iv)

Gravity
Chapter-4   Work, Energy, Power
Q-1 Answer the following questions.
(a) Define work.
(b) Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
(c) What is the work done in holding a 5 kg suitcase while waiting for a train for 10 minutes? Give reason for your answer.
(d) Define energy and power and state their SI units.
(e) Define KE and PE. Also state the law of conservation of energy.
(f) Distinguish between PE and KE and give two examples of each.
(g) Under what condition is a body said to possess energy?
(h) How will you justify that the total mechanical energy is conserved?
(i) Give examples of bodies possessing both PE and KE at the same time.
(j) A light mass and a heavy mass have equal momentum. Which will have more KE? Explain.
Q-2 State and define:
(a) The SI unit of work
(b) CGS unit of work
Q-3 A string, suspended from a fixed point, has a small mass swinging to and fro at the other end. With respect to the string, state whether the following statements are true or false.
(a) The PE is the maximum in the centre position of the swing.

(b) The KE is the maximum in the centre position of the swing.

(c) The sum of PE and KE is constant throughout the swing.
(d) The number of swings decrease with time.
Q-4 Name three sources of energy that are:
(a) renewable as well as inexhaustible
(b) renewable but exhaustible
Q-5 Outline the steps to show how the following can be converted into electrical energy:
(a) Sunlight
(b) Tides
(c) Wind
Q-6 Classify the following examples into KE and PE:
(a) A wound spring
(b) Flowing water
(c) A stretched bow string
(d) Water stored on a mountain top
(e) A bullet fired from a gun
(f) An electron spinning around the nucleus
Q-7 State the energy changes that take place in the following:
(a) Water in the freezer of a refrigerator turns to ice.
(b) A photographic film is exposed.
(c) An electric bell rings.
(d) The food consumed is digested.
(e) Water from dams rotate the turbines of a dynamo.
(f) A nuclear reactor.
Q-8 Fill in the blanks:
(a) The kinetic energy of a moving body is 30J. If it is moving with a speed of 2m/s, then its mass is _____________ .
(b) horse power is equal to _______ W.
Multiple Choice Questions
Q-1 

Work done by a person standing and holding a suitcase weighing 6 kg (g = 10m/s2)

(i)

60J

(ii)

600J

(iii)

54J

(iv)

Zero

(v)

42.BJ

(vi)

4.1 BJ

(vii)

0.26J
Q-2 How many joules are there in 1 calorie?

(i)

0.24J

(ii)

0.26J

(iii)

4.1 BJ

(iv)

42.BJ
Q-3 The work done on an object depends upon:

(i)

Displacement

(ii)

Force applied

(iii)

Initial velocity

(iv)

Both a and b
Q-4 Unit of work done in SI unit is:

(i)

newton metre

(ii)

Calorie

(iii)

watt

(iv)

joule
Q-5 Work done by the person when a load of 1 00N is lifted through a height of 20 m is:

(i)

5J

(ii)

2000J

(iii)

200W

(iv)

zero
Q-6 An object having the capability to do work is said to possess:

(i)

Inertia

(ii)

Energy

(iii)

Force

(iv)

Power
Q-7 Which is not a unit of energy?

(i)

watt hour

(ii)

kilowatt hour

(iii)

watt

(iv)

joule
Q-8 The rate of doing work is equal to:

(i)

Power

(ii)

Work

(iii)

Energy

(iv)

Pressure
Q-9 Which statement is true:

(i)

SI unit of power and energy is the same

(ii)

Work does not depend on time but power depends on time

(iii)

Power = Work x time

(iv)

Power and Work are vector quantities
Q-10 The power is consumed to perform 260 J of work in 26 seconds is:

(i)

6760 W

(ii)

10W

(iii)

6760J

(iv)

10W/s
Q-11 

The kinetic energy of an object increases if the increases.

(i)

Friction

(ii)

Time

(iii)

Velocity

(iv)

Distance
Q-12 In which of the following case does the PE decrease?

(i)

On compressing a spring

(ii)

On stretching a spring

(iii)

On free fall of an object

(iv)

On throwing an object upwards
Q-13 The energy change in a loudspeaker is from:

(i)

Sound energy to mechanical energy

(ii)

Sound energy to electrical energy

(iii)

Electrical energy to sound energy

(iv)

Mechanical energy to electrical energy
Q-14 

1 kWh = ________

(i)

3.6 X 106 J

(ii)

3600J

(iii)

3.6 X 105J

(iv)

36000J
Q-15 

A mass of 10kg is at a height of 5 m above the ground. The potential energy possessed by the body is (g = 10m/s2):

(i)

50J

(ii)

50W

(iii)

500J

(iv)

500N
Chapter-5   Light
Q-1 A ray is incident on a glass block as shown below:
(a) Complete the ray diagram until the ray emerges from the block.
(b) Clearly label on the diagram the following: {i) Refracted ray {ii) Angle of incidence {iii) Angle of refraction {iv) Normal
Q-2 Fill in the blanks:
(a) When a ray of light travels from a rarer medium to a denser medium, it bends ______ the normal.
(b) When a ray of light travels from a denser to a rarer medium, it bends ______ the normal.
(c) The speed of light is ______ in air or in vacuum.
(d) If a ray, after refraction bends away from the normal, then the angle of incidence is __________ than the angle of refraction.
(e) The refractive index of ______ colour is maximum and that of ______ colour is minimum.
Q-3 Draw a ray diagram to show the path of a monochromatic ray of light as it enters a prism and emerges from the refracting surface. Label the following in the diagram:
(a) incident ray (from air to glass)
(b) emergent ray
(c) angle of refraction (from glass to air)
(d) angle of deviation
(e) angle of incidence (from glass to air)
(f) angle of emergence
Q-4 State whether the following statements are true or false:
(a) In a prism, the angle of deviation depends on the material of the prism.
(b) A ray of light after passing through the prism always bends towards its base.
(c) The speed of light in a given medium depends on the density of the medium.
(d) When light passes through a prism, the value of the angle of deviation increases if the angle of incidence in increased.
(e) When a ray of light is incident normally on a surface separating two media, it passes through undeviated.
(f) For a normal incident ray, the refractive index is 1.
(g) The speed of light of violet colour is more than that of red.
(h) The speed of light in vacuum is 300,000 m/s.
(i) A light year is the distance travelled by light in one year.
Q-5 Identify the type of spherical mirror shown below. Label the following parts:
(a) (i) Pole (ii) Radius of curvature (iii) Centre of curvature (iv) Focus (v) Focal length (vi) Principal axis
(b) Write the relation between the radius of curvature and focal length of the mirror.
(c) Place an object beyond the centre of curvature. Draw two rays from it and show how the image is formed.

(d) Describe the nature of the image formed.

Q-6 Draw ray diagrams to show the nature of image formed when the object is at the following positions.

An object is placed beyond C of a concave mirror. If the object is slowly moved towards the mirror will the image size increase or decrease?

(a) At C
(b) Between C and F
(c) At F
Q-7 Answer the following questions.
(a) Draw a neat ray diagram of an image formed by: (i) An object placed in front of a convex mirror. (ii) An object placed between P and F of a concave mirror.
(b) Compare the nature of images formed by the mirrors in 7 (a).
Q-8 Write Concave or Convex in the blanks.
(a) Shaving mirror __________________
(b) Car headlight mirror _______________
(c) Searchlight mirror _________________
(d) Driving mirror _______________
(e) Dentist's inspection mirror _________________
(f) Torch mirror ________________
(g) Projector lamp mirror _______________
(h) Solar furnace mirror _______________
Q-9 State the position of the object (with respect to a convex lens) given the following image characteristics.
(a) Image is real, inverted, highly diminished and at second focus on the other side of the lens.
(b) Image is at 2F on the other side of lens, real, inverted and diminished.
(c) Image is formed on the same side of the object, erect and magnified.
(d) Image is at infinity on the other side of the lens, real, inverted and highly magnified.
(e) The image is beyond 2F on the other side of the lens, real, inverted and magnified.
Multiple Choice Questions
Q-1 The velocity of light passing from a rarer medium to a denser medium:

(i)

Increases

(ii)

Remains same

(iii)

Decreases

(iv)

None of these
Q-2 The velocity of light is maximum in:

(i)

Water

(ii)

Air

(iii)

Glass

(iv)

Diamond
Q-3 Which one is optically the densest medium?

(i)

water

(ii)

Glass

(iii)

Air

(iv)

All are same
Q-4 The velocity of light in air is:

(i)

2 x108 m/s

(ii)

2.25 x 108 m/s

(iii)

3 x 108 cm/s

(iv)

3 x 108 m/s
Q-5 When a ray of light travels from a rarer medium to a denser medium:

(i)

R.I of medium = Velocity of light in medium / Velocity of light in air

(ii)

R.I of medium = Velocity of light in air x velocity of light in medium

(iii)

R.I of medium = Velocity of light in air / Velocity of light in medium

(iv)

R.I of medium = 1`
Q-6 When a ray of light is incident normally on a surface separating two media:

(i)

It bends towards the normal

(ii)

It bends away from the normal

(iii)

It passes undeviated

(iv)

None of the these
Q-7 If a ray of light passes from glass to air, then:

(i)

Lr = L i

(ii)

Lr < Li

(iii)

45

(iv)

Lr > L i
Q-8 In a glass prism, the angle of deviation depends upon:

(i)

Angle of prism

(ii)

Base of prism

(iii)

Refracting surface

(iv)

None of these
Q-9 The main characteristic of colour of light is its:

(i)

Velocity

(ii)

Wavelength

(iii)

Intensity

(iv)

Frequency
Q-10 White light is:

(i)

Monochromatic

(ii)

Polychromatic

(iii)

Technicolour

(iv)

None of these
Q-11 A stick partially immersed in water appears bent due to:

(i)

Reflection of light

(ii)

Dispersion of light

(iii)

Refraction of light

(iv)

Absorption of light
Q-12 Refractive index of __________ colour is maximum and that of _________ colour is least.

(i)

Red and violet

(ii)

Blue and violet

(iii)

Violet and red

(iv)

Yellow and blue
Q-13 The geometric centre of the spherical mirror surface is called:

(i)

Centre of curvature

(ii)

Focus

(iii)

Centre of the pole

(iv)

Pole
Q-14 When an object is at infinity for a spherical mirror, the image will be formed:

(i)

At infinity

(ii)

Beyond centre of curvature

(iii)

At the focus

(iv)

Between focus and pole
Q-15 A ______ mirror is used for rear view mirror and ____ mirror is used as shaving mirror.

(i)

Concave, convex

(ii)

Plane, convex

(iii)

Concave, plane

(iv)

Convex, concave
Chapter-6   Heat Transfer and Thermal Expansion
Q-1 Answer the following questions.
(a) Differentiate between heat and temperature.
(b) Explain the term 'Thermal Equilibrium'.
(c) Name and define the modes of heat transfer in matter.
(d) State the difference between conductors and insulators.
(e) Explain what is meant by thermal expansion.
(f) Describe an experiment to demonstrate that metals expand on heating.
Q-2 Give two examples of each:
(a) Good conductors of heat
(b) Poor conductors of heat
Q-3 The diagram below shows a bimetallic strip at room temperature. Draw a simple diagram to show its shape:
(a) When heated over a strong flame
(b) When it is cooled
Q-4 The diagram shown is that of an iron washer. State whether the following qualities will increase, decrease or remain unchanged when it is heated.
(a) external diameter
(b) internal diameter
(c) mass
(d) density
Q-5 The following paragraph refers to the anomalous behaviour of water. Fill in the blanks and complete the paragraph.
When water is cooled it ______ upto 4°C. On further cooling it ______ up to 0°C. Thus, at 0°C water has the ______ volume and ______ density. When ice at ______ °C is heated it ______ up to ______ °C. Thus, at ______ °C water has minimum ______ and maximum __________ .
Q-6 Explain :
(a) Convection does not occur in solids.
(b) Gases are poor conductors of heat.
(c) Convection is important in heating and insulating homes.
(d) The presence of a large water body (sea/ocean) tends to moderate the temperature extremes of climate on adjacent land.
(e) If a mercury thermometer with a thick glass bulb is plunged into a hot liquid, the mercury first falls slightly and then rises quickly.
(f) If boiling water is poured into a tumbler the tumbler may crack.
(g) A stopper may often be loosened by heating the neck of the bottle.
(h) Long lengths of pipes carrying hot liquids often have loops in them.
(i) Gaps are left in railway lines.
(j) A thermostat is used in heaters and geysers.
(k) Iron tyres of cart wheels are heated before fitting.
Multiple Choice Questions
Q-1 ________________ is the process of heat transfer in solids:

(i)

Convection

(ii)

Conduction

(iii)

Evaporation

(iv)

Boiling
Q-2 The SI unit of heat is ______ and that of temperature is ______

(i)

erg, °C

(ii)

joule, °F

(iii)

joule, kelvin

(iv)

erg, K
Q-3 On heating a body, heat energy is _____________ and on cooling it heat energy is ______________

(i)

Absorbed, released (given out)

(ii)

Released, absorbed

(iii)

Absorbed, absorbed

(iv)

Released, released
Q-4 Total energy is the measure of:

(i)

Temperature

(ii)

Heat

(iii)

Light

(iv)

Expansion
Q-5 When a substance is heated:

(i)

Kinetic energy decreases

(ii)

Temperature decreases

(iii)

No change in temperature

(iv)

Kinetic energy increases
Q-6 Liquids expand:

(i)

Less than solids

(ii)

More than gases

(iii)

More than solids

(iv)

Less than solids and gases
Q-7 Expansion in length is ______ while expansion in volume is ________

(i)

Linear, cubical

(ii)

Linear, superficial

(iii)

Cubical, superficial

(iv)

Superficial, linear
Q-8 Unit of expansion is:

(i)

kelvin

(ii)

°C

(iii)

per °Celsius

(iv)

°F
Q-9 Rods A and Bare made up of different materials but are of the same length. After heating both of them through the same rise in temperature, the rods expand as shown below:

(i)

A has a smaller coefficient of linear expansion than B

(ii)

A and B both have the same coefficient of linear expansion

(iii)

A and B both do not have coefficient of linear expansion

(iv)

A has a greater coefficient of linear expansion than B
Q-10 Î² represents coefficient of:

(i)

Linear expansion

(ii)

Superficial expansion

(iii)

Cubical expansion

(iv)

None of these
Q-11 Expansion in an object due to heat is called:

(i)

Thermal expansion

(ii)

Linear expansion

(iii)

Cubical expansion

(iv)

Superficial expansion
Q-12 The energy transfer from the Sun to the Earth is by:

(i)

Conduction.

(ii)

Convection

(iii)

Radiation

(iv)

Expansion
Q-13 A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z:

(i)

Must be in thermal equilibrium

(ii)

Cannot be in thermal equilibrium

(iii)

May be in thermal equilibrium

(iv)

None of these
Chapter-7   Sound
Q-1 Answer the following questions.
(a) How is sound produced and propagated?
(b) If 'v' stands for the velocity of a wave, 'f' for the frequency of the wave and ''A' for the wavelength, derive an equation relating v, f and 'A.
(c) A tuning fork has a frequency of 51 2 Hz. What is the wavelength of the sound wave produced in the air? (Take velocity of sound in air = 340 ms- 1)
(d) Find the wavelengths in air and in water of sound waves of frequency 20 Hz and 20,000 Hz. (Take velocity of sound in air = 340 ms-1; velocity of sound in water = 1480 ms- 1)
(e) State three differences between noise and musical sound.
Q-2 The diagrams A and B represent two types of wave motion.
(a) How many waves are shown in diagram A?
(b) How many waves are shown in diagram B?
(c) Name the regions labelled X and Y in diagram B.

(d) Name the type of wave which is produced when: (a) A stone is dropped into a pond. (b) A tuning fork is struck in air.

Q-3 Fill in the blanks :
(a) Frequency is _______ proportional to wavelength.
(b) Any continuous sound that does not change pitch is said to be a ___________ .
(c) Vibrations which produce sounds below the normal hearing range of humans are known as _______ sounds.
(d) Loud sound is produced by sound waves with _______ amplitude.
(e) Intensity of sound is _______ proportional to the density of medium in which it propagates.
(f) The sound waves produced in a sitar (string instrument) is an example of ________ waves, while the sound waves produced in a temple bell is an example of __________ waves.
Q-4 State whether the following statements are true or false.
(a) Sound travels fastest in gases.
(b) Wavelength is the distance between a consecutive crest and a trough.
(c) Velocity of sound is independent of the frequency, wavelength and loudness of sound.
(d) The time taken to complete one vibration is called the time period of the sound wave.
(e) Loudness of sound is measured on a scale called the Richter Scale.
Q-5 State how sound is produced in:
(a) Wind instruments
(b) String instruments
(c) Percussion instruments
Q-6 Explain:
(a) The wing of insects produces a shrill sound.
(b) Soldiers are made to break step while crossing a bridge.
(c) Men have a low pitched voice.
(d) In outer space, astronauts use radios to communicate with one another.
Multiple Choice Questions
Q-1 Sound wave A travels through water and sound wave B travels through air. Wave A travels:

(i)

Faster than B

(ii)

Slower than B

(iii)

Same speed as B

(iv)

None of these
Q-2 The audible range of the human hearing is:

(i)

20Hz to18,000 Hz

(ii)

< 20 Hz

(iii)

> 20000 Hz

(iv)

20Hz to 20,000 Hz
Q-3 Pitch of sound is determined by its:

(i)

Frequency

(ii)

Speed

(iii)

Amplitude

(iv)

Velocity
Q-4 Sound cannot travel through:

(i)

Water

(ii)

Air

(iii)

Vacuum

(iv)

Steel
Q-5 The number of vibrations made by a vibrating body in one second is:

(i)

Loudness

(ii)

Amplitude

(iii)

Pitch

(iv)

Frequency
Q-6 Above ______ dB, the sound becomes physically painful.

(i)

120

(ii)

60

(iii)

40

(iv)

80
Q-7 The frequency of a tuning fork is 256 Hz. If the speed of sound is 340 m/s, the wavelength is:

(i)

0.75 m

(ii)

1.32 m

(iii)

7.5 m

(iv)

13.2 m
Q-8 Two waveforms, wave A and wave Bare shown below. Select the true statement:

(i)

A has a higher pitch than B

(ii)

A produces a louder sound than B

(iii)

B produces a louder sound than A

(iv)

Both A and B have the same loudness
Q-9 Two types of waveforms are shown below. Select the true statement:

(i)

Wave A is a transverse wave and wave B is a longitudinal wave

(ii)

Wave A is a longitudinal wave and wave B is a transverse wave

(iii)

Wave A and wave B are transverse waves

(iv)

None of the above
Q-10 A pendulum oscillates 20 times in 4 seconds. Its time period is:

(i)

0.5 s

(ii)

5 s

(iii)

1 s

(iv)

0.2 s
Q-11 An instrument used in the laboratory to produce sound of fixed frequency is:

(i)

String instrument

(ii)

Wind instrument

(iii)

Tuning fork

(iv)

Drums
Q-12 The characteristic of sound which helps to recognise voices without seeing the person is:

(i)

Quality or timbre

(ii)

Pitch

(iii)

Loudness

(iv)

Resonance
Q-13 If an object vibrates under the influence of an applied periodic force which increases the amplitude of vibrations, the phenomenon is called:

(i)

Echo

(ii)

Resonance

(iii)

Both a and b

(iv)

None of these
Q-14 The velocity of sound in solids is _______ the velocity of sound in liquids.

(i)

Same as

(ii)

Greater than

(iii)

Less than

(iv)

Both band c
Chapter-8   Static Electricity
Q-1 Answer the following questions.
(a) What is meant by electrification by friction?
(b) How can you produce two kinds of charges using fur, glass, ebonite and silk?
(c) An ebonite rod is rubbed with fur and held near two small metal spheres M, and M2 which are suspended by long silk threads and are in contact with each other. (i) First the metal spheres are seen to separate. Explain this observation. (ii) If the rod is taken away, what charges will appear on M, and M/ Explain your answer.
(d) A body A is to be charged positively by using another charged body B. What should be the type of charge on the body B if charging is done: (i) by conduction? (ii) by induction?
(e) What is a gold leaf electroscope?
(f) State any one application of a gold leaf electroscope.
(g) Describe briefly how lightning is caused.
(h) Explain how a lightning rod protects buildings from lightning strikes.
Q-2 Name the charges produced on each of the substances:
(a) When ebonite rod is rubbed with catskin.
(b) Glass rod is rubbed with silk.
Q-3 State what happens under the following conditions:
(a) An ebonite rod is rubbed with fur.
(b) An ebonite rod rubbed against flannel is brought near a charged glass rod.
(c) A glass rod rubbed with silk is brought near a charged ebonite rod.
(d) An ebonite rod is brought near a freely suspended glass rod.
(e) An ebonite rod is brought near a freely suspended and charged ebonite rod.
Q-4 A pith ball A is suspended between a positively charged sphere B and an earthed metal plate C. It is observed that the pith ball swings towards B, then to C and then back to B and so on. After some time the motion stops. Explain:
(a) Why does the pith ball swing towards B?
(b) Why does it return and move towards C?
(c) Why does the motion stop?
Q-5 In the diagram alongside, A is a positively charged electroscope and B is an earthed conductor. What will happen when:
(a) B is brought near the metal plate of the electroscope?
(b) B is then taken away?
Multiple Choice Questions
Q-1 Two atomic particles make the nucleus:

(i)

Proton and electron

(ii)

Neutron and proton

(iii)

Electron and neutron

(iv)

Photon and nucleus
Q-2 A plastic rod is rubbed with a piece of fur. The rod acquires a negative charge. Fur gets:

(i)

A positive charge but greater in magnitude than fur

(ii)

A negative charge but more than the rod

(iii)

A positive charge with the same magnitude as the rod

(iv)

Negative charge but less than the rod
Q-3 A positively charged rod is brought close to one end of a neutral metallic plate. The type of charge induced on the closest side of the plate is:

(i)

Positive

(ii)

Negative

(iii)

Neutral

(iv)

None of these
Q-4 When a positively charged rod is brought near a charged electroscope the leaves move closer to each other. The charge on the electroscope is:

(i)

Negative

(ii)

Positive

(iii)

Neutral

(iv)

Both a and b
Q-5 A neutral electroscope is touched with a positively charged rod. After removing the rod the electroscope is charged positively because of:

(i)

Induction

(ii)

Photo emission

(iii)

Conduction

(iv)

Both a and b
Q-6 A neutral electroscope is touched with a negatively charged rod. The charge on the electroscope after the rod is removed will be:

(i)

Positive

(ii)

Negative

(iii)

Neutral

(iv)

Both a and b
Q-7 A negatively charged rod is brought near an uncharged grounded electroscope:

(i)

A positive charge flows from the electroscope to the ground

(ii)

A positive charge flows from the ground to the electroscope

(iii)

A negative charge flows from the ground to the electroscope

(iv)

A negative charge flows from the electroscope to the ground
Q-8 Lightning is an example of:

(i)

Conduction

(ii)

Induction

(iii)

Static electricity

(iv)

Both a and b
Q-9 In an atom, the _______ are in a constant state of motion while ______ and ________are stationary.

(i)

Neutrons, protons, electrons

(ii)

Protons, electrons, neutrons

(iii)

Electrons, neutrons, protons

(iv)

Electrons, photons, neutrons
Q-10 To detect the presence of a weak electric charge and the nature of charge on a body, device used is:

(i)

An electroscope

(ii)

Gold leaf electroscope

(iii)

Pith ball electroscope

(iv)

All of these
Q-11 Static electricity can be generated only in:

(i)

A conductor

(ii)

Semiconductor

(iii)

Insulators

(iv)

Any material
Q-12 Trucks carrying petrol have a chain extending from the body to the ground to protect it from catching fire due to sparking. This method is called:

(i)

Lightning

(ii)

Earthing

(iii)

Anti sparking

(iv)

None of these
Chapter-9   Current Electricity
Q-1 Answer the following questions.
(a) Name the two types of electricity and state one fundamental difference between them.
(b) List three main sources of obtaining electricity.
(c) What are the two basic requirements for an electric current to flow?
(d) What is a liquid that conducts electricity called? How is the charge carried in liquid conductors?
(e) Explain the meaning of power-voltage rating of an appliance.
(f) What is meant by a 'short circuit'? Why does it occur?
(g) Draw a neatly labelled diagram to show a short circuit.
(h) What are the dangers associated with a short circuit?
(i) What is a fuse? What is the function of a fuse in an electric circuit?
(j) Why is the fuse connected to the live wire?
(k) Name the material of the fuse.
(l) Why it is dangerous to touch a switch with wet hands?
(m) How does earthing protect the user from receiving electric shock?
(n) Which part of an electric appliance is earthed and why?
(o) How is a household circuit earthed?
(p) An electric bulb is rated 100W - 250V. What does this mean?
Q-2 What is an electric circuit? With respect to the flow of an electric current complete the following sentences:
(a) In conductors, some electrons can move from one atom to another. These electrons are called _______ electrons.
(b) Conventionally, the direction of electric current is always from the ______ to the ________ terminal.
(c) The flow of _______ in a circuit is called current.

(d) If charge is measured in coulomb and time in second, the unit of current is coulomb per second and is called __________

(e) Current is a _______ quantity.
Q-3 State whether the following statements regarding a voltmeter are true. Correct the incorrect statements.
(a) Voltmeters are connected in a circuit in series.
(b) A voltmeter is used to measure current.
(c) Voltage is measured in volt.
(d) When the number of batteries are increased, the voltage increases and the bulb glows more and more brightly.
(e) The positive terminal of the voltmeter must be connected to the part of the circuit nearest the positive terminal of the cell.
Q-4 As per the new International convention, what is the colour assigned to each of the following:
(a) Live wire
(b) Neutral wire
(c) Earth wire
Q-5 A lady received a shock when she happened to touch an electric kettle even though the switch was off.
(a) State the possible reasons for the shock.
(b) Point out the possible defect with the electric wiring inside the kitchen.
Q-6 What are the precautions to be taken while:
(a) Repairing or replacing any electrical component?
(b) Dealing with a shock victim?
Q-7 Fill in the blanks:
(a) The unit of electrical power is _________ .
(b) The electric meter fixed at the mains board in houses and factories measures the consumed electrical energy in _________ .
(c) Electricity is produced mainly by __________ and _________
(d) Current is measured in _______ using an _______ placed in _______ in a circuit
(e) The values of the voltage and wattage of an electrical appliance taken together is called its ____________
(f) Fuses should be connected to the ______ wire.
(g) Energy consumed in kWh = _________________
(h) 1 kWh = ___________ J.
(i) 1 Wh = _________ J.
Q-8 Answer the following questions.

(a) An electric bulb taking in a current 0.25A works on electric mains of pd 240V. Calculate the power of the bulb.

(b) An electric bulb of power 1 00W is used in a house for 5 hours everyday. How much electrical energy will it consume in 30 days? What would be the cost of energy at the rate of ~ 4 per unit?

(c) In a restaurant 10 lamps of 60 watt each are used for 6 hours a day while 4 fans of 100 watt each and a radio of power 50W are used for 10 hours a day. Calculate the cost of electrical consumption at the rate of 5 for the month of June. If the rent of the meter be ~50 per month, Calculate the bill for electrical consumption.
(d) Three appliances of power 60W, 120W and 300W are simultaneously working in a circuit. Calculate the total power of the circuit. If they work for 2 hours, how much energy would be consumed?

(e) How much does it cost to run one heater of 1000W and two light bulbs of 40W, each for 8 hours if one unit of electricity costs 3?

Q-9 A refrigerator is marked SOW and 220V
(a) How much energy does it consume in one day if on average it is used for 20 h a day?
(b) What is likely to happen if the voltage drops to 50V?
Q-10 A household uses the following:

(a) Four 100W, 250V lamps on an average of 10 hours a day.

(b) A 500W, 250V electric iron on an average of 30 minutes a day.
(c) A 2kW, 250V electric geyser on an average of two hours a day. Calculate the number of kWh units consumed in 30 days and the cost of consumption at ~4.50 per unit.
Multiple Choice Questions
Q-1 The main source of electricity:

(i)

Electric circuit

(ii)

Cells and batteries

(iii)

Voltmeter

(iv)

Ammeter
Q-2 Ammeter is connected in ________ and voltmeter is connected in ________

(i)

Parallel, series

(ii)

Parallel, parallel

(iii)

Series, parallel

(iv)

None of these
Q-3 To measure the magnitude of current, the device used is:

(i)

Voltmeter

(ii)

Connecting wires

(iii)

Galvanometer

(iv)

Ammeter
Q-4 To measure the potential difference across the load, the device used is:

(i)

Voltmeter

(ii)

Galvanometer

(iii)

Ammeter

(iv)

None of these
Q-5 Material used as connecting wires:

(i)

Copper with a low resistance

(ii)

Tungsten with a low resistance

(iii)

Fuse with a high resistance

(iv)

Both a and b
Q-6 Rating of an appliance is used to calculate:

(i)

Resistance of the appliance

(ii)

Safe limit of the current for the appliance

(iii)

Electric energy consumed in given time

(iv)

All of these
Q-7 The new convention for colour coding of wires is:

(i)

Green --------> Live; Light blue --------> Neutral; Brown -------> Earth

(ii)

Brown -----------> Live; Green ----------> Neutral; Light blue --------> Earth

(iii)

Brown -----------> Live; Light blue ----------> Neutral; Green or yellow ----------->Earth

(iv)

Yellow-------------> Earth; Green or yellow -----------> Live; Light blue -----------> Neutral
Q-8 Short circuits are caused when:

(i)

Live and neutral wires come in direct contact

(ii)

Neutral and earth wires come in direct contact

(iii)

Live and earth wires come in direct contact

(iv)

All three wires are open in circuit
Q-9 Device used to protect electric circuits from fires and save the appliance is:

(i)

Socket

(ii)

Plug

(iii)

Fuse

(iv)

Earthing
Q-10 Means to protect the person handling electrical appliances from getting an electric shock:

(i)

Earthing

(ii)

Fuse

(iii)

Switch

(iv)

Socket
Q-11 The special instrument used to calculate the consumed electric energy in kWh is:

(i)

Fuse

(ii)

Power meter

(iii)

Ammeter

(iv)

Voltmeter
Q-12 The current rating of a fuse helps to protect:

(i)

Sockets and plugs

(ii)

Earthing and switches

(iii)

Electric circuits and appliances

(iv)

Electric wires and sockets
Q-13 The commercial unit of electric energy is:

(i)

Kilowatt

(ii)

Watt

(iii)

Kilowatt hour

(iv)

None of these
Q-14 Fuse is always connected in _______ to the _______ wire.

(i)

Parallel, live

(ii)

Series, live

(iii)

Series, neutral

(iv)

Parallel, neutral
Q-15 

In India the electricity supply in homes is of _______

(i)

110V

(ii)

100W

(iii)

220V

(iv)

1000W