Question 9
(a) (i) State three advantages of the constant-volume gas thermometer over the liquid-in-glass thermometer.
(ii) A resistance thermometer registers a resistance of 9000 Ω at steam point and resistance of 720 Ω at 48 oC, Determine the resistance registered on the thermometer at ice point.
(b) State three functions of the transparent glass cover used in solar panels.
(c) (i) Explain land breeze and sea breeze in terms of specific heat capacities of the land and the sea.
(ii) State two applications of the cooling effect of evaporation.
Observation
Part (a) Performance was below average.
Part (b) Performance was below average.
Part (c) Performance was below average.
The expected responses:
(a) (i) Advantages of the constant-volume gas thermometer over the liquid-in-glass
- Thermometer: It
- is more sensitive to temperature change
- has wider range of temperature
- is more accurate
- has lower thermal capacity
- it reduces heat loss in the upward direction from the absorber plate
- allows maximum solar energy transmission to the metal plate
- shields the absorber plate from direct exposure to harsh weather condition
- During the day, the land gets warm faster than the sea because of the lower specific heat capacity of the land.
- Cool air from the sea blows towards the land to replace the warm rising air on the surface of the land.
- In the night, because of the higher specific heat capacity of the sea, it is warmer than the land.
- Cool air from the land blows towards the sea to displace the warm rising air from the sea.
- Cooling of the body after sweating
- In the cooling process of refrigerator/air conditioner.
- In the cooling of water in clay pot.
(ii)Determination of the resistance at ice point
(b)Functions of the glass cover used in solar panels:
(c)(i) Explanation of land breeze and sea breeze
(ii) Application of the cooling effect of evaporation