On a day when the temperature is 20 °C, steel train rails are laid in 12 m long segments, placed end to end. How much space must be left between adjacent rails if they are just to touch on a hot day when the temperature is 40 °C? (Hint: Take the linear expansivity of steel to be 9 × 10⁻⁷ (°C)⁻¹.)
Answer :
Question No. 2
The longest bridge in Nigeria is the 11.8 km long Third Mainland Bridge connecting Lagos Island to the mainland. What temperature change would cause a 25 m concrete span of the bridge to expand by 10 mm? (Hint: Take the linear expansivity of concrete to be 9.8 × 10⁻⁶ (°C)⁻¹.)
Answer :
Question No. 3
The Eiffel Tower in Paris, France, was constructed in 1889 by Alexandre Eiffel. The tower structure is made of steel. If the tower is 301 m high on a day on which the temperature is 22 °C, by how much will the height decrease when the temperature cools down to −2 °C on a very cold day in Paris? (Hint: Take the linear expansivity of steel to be 9 × 10⁻⁷ (°C)⁻¹.)
Answer :
Question No. 4
Aluminium rivets used in aeroplane construction are made slightly larger than the rivet holes. The rivets are cooled to −78 °C before being inserted into a rivet hole of diameter 4.50 mm. What must the diameter of the rivet be at manufacturing stage when the temperature is 22 °C? (Hint: Take the area expansivity of aluminium to be 4.8 × 10⁻⁵ (°C)⁻¹.)
Answer :
Question No. 5
A cook struggles to loosen the lid on a jar of pickles. Both the outer diameter of the glass jar opening and the inner diameter of its iron lid are 500 mm at a room temperature of 25 °C. The cook puts the jar under hot water until the temperature of the jar and lid reaches 50 °C. Will the lid come off the jar? Use calculations to prove your answer. (Hint: The volume expansivity of glass is 1.4 × 10⁻⁵ (°C)⁻¹ and that of iron is 3.6 × 10⁻⁵ (°C)⁻¹.)
Answer :
Question No. 6
A copper flask with a volume of 200 cm³ is filled to the brim with olive oil at room temperature of 25 °C. If the flask and its contents are heated to a temperature of 40 °C, how much oil spills from the flask? (Hint: The volume expansivity of copper is 5.1 × 10⁻⁵ (°C)⁻¹ and that of oil is 6.8 × 10⁻⁴ (°C)⁻¹.)
Answer :
Question No. 7
Temperature is a measure of the average:
Answer :
Question No. 8
A block of metal is heated until its temperature is above its melting point. Which one of the following will not change as a result of the heating?
Answer :
Question No. 9
Which one of the following does not need a medium for the transfer of heat?
Answer :
Question No. 10
You place your hand above an electric heater. The heat is transferred to your hand by:
Answer :
Question No. 11
Equal quantities of very hot water are poured into a dull black teapot and a teapot with a shiny surface. After 30 minutes, in which teapot will the temperature of the water be higher and for what reason?
Answer :
Question No. 12
Metal rod A is twice as long as Metal rod B. When both rods are heated to increase their temperatures by the same amount (ΔT), they have the same increase in length. We can conclude that the linear expansivity of Rod A is:
Answer :
Question No. 13
When water is boiled in an electric urn, the transfer of heat to the water is mainly by:
Answer :
Question No. 14
The boiling point and melting point of carbon dioxide are –57 °C and –78 °C, respectively. In what state will carbon dioxide be at a temperature of 0 °C?
Answer :
Question No. 15
The human body produces large amounts of perspiration (sweat) on very hot days. This helps to keep the body cool because the perspiration:
Answer :
123456789101112131415
Answered
1Not Answered
1Not Visited
0Marked For Review
9Answered & Marked for review (will be considered for
evaluation)
