Chapter 3
1. The temperature of hot and cold substances is measured using ……
A.
B.
C.
D.
Barometer
Thermometer
Hydrometer
Manometer
2. When the liquid are cooled, their densities ……
A.
B.
C.
D.
Increase
Decrease
Change
Do not change
3. The rate of heat flow is called …..
A.
B.
C.
D.
Heat current
Thermal conductivity
Temperature
Temperature gradient
4. For a black body the radiation law is represented by the equation …..
A. 𝜀0 = 𝜎𝑇 4
B. 𝐻 = 𝑞𝐴(𝑇2 − 𝑇1 )
C. 𝐻 =
𝜅𝐴(𝑇2 −𝑇1 )
𝑙
D. 𝜀 = 𝑒𝜀0
5. The …… surface are the best emitter of radiant energies.
A.
B.
C.
D.
White
Black
Violet
Blue
6. The …… is the major source of heat for the earth.
A.
B.
C.
D.
Sun
Moon
Star
Planet
7. Heat conduction takes place in …… medium.
A.
B.
C.
D.
Liquid
Solid
Gas
Fluid
13. The …… body is taken as a reference body in study the emissivity of a body.
A.
B.
C.
D.
White
Black
Violet
Blue
14. The air trapped in woolen fibers acts as…….
A.
B.
C.
D.
Conductor
Insulator
Heater
Semiconductor
15. Heat is most closely related to …..
A.
B.
C.
D.
Energy
Temperature
Force
Pressure
16. We obtain energy from the sun by…….
A.
B.
C.
D.
Conduction
Convection
Radiation
Thermal conduction
17. When the convection currents set up in the air of room,
A.
B.
C.
D.
Density of hot air increased
Air contracts when heated
Hot air rise to the top
Hot air sink to the bottom
18. A solar heater uses energy from the sun to heat water. The panel of the heater is painted…….
A.
B.
C.
D.
White
Black
Yellow
Red
19. The best absorber of inferred radiation is ……
A.
B.
C.
D.
White paper
Shiny metal
Dark animal fur
Blue cloths
20. From the following the best insulator is ……
A.
B.
C.
D.
Wood
Vacuum
Air
Plastic
21. Transfer of heat in ----- is mainly due to heat convection.
A.
B.
C.
D.
Solid
Liquid
Gas
Fluid
22. The weather conditions near the coastal region are ------ by heat convection.
A.
B.
C.
D.
Hot
Cold
Fair
Not change
23. The emissivity of the black body is -----.
A.
B.
C.
D.
0
1
2
3
24. The total emissive power of other body is -----.
A. 𝜀0 = 𝜎𝑇 4
B. 𝐻 = 𝑞𝐴(𝑇2 − 𝑇1 )
C. 𝐻 =
𝜅𝐴(𝑇2 −𝑇1 )
𝑙
D. 𝜀 = 𝑒𝜀0
25. The velocity of thermal radiation is ------.
A.
B.
C.
D.
332 ms­1
3 x 108 ms­1
3 x 10­8 ms­1
3.1 x 108 ms­1
26. The SI unit of total emissive power is ------.
A.
B.
C.
D.
Wm­2
Wm­1K­1
Wm­2K­1
Wm­2K­4
27. The temperature of the 450 K is equivalent to Celsius temperature of……
A.
B.
C.
D.
723˚
10˚
273˚
177˚
28. Dark, rough object are generally good for……
A.
B.
C.
D.
Conduction
Convection
Radiation
Reflection
29. Dark plastic handles are often used on kitchen utensil because
A.
B.
C.
D.
A black material is a good radiator
The plastic is a good insulator
The plastic is a good conductor
Plastic is softer gradually with excessive heat
30. The temperature of 100˚C is equivalent to ­­­­­.
A.
B.
C.
D.
0K
173 K
273 K
373 K
(31) When the temperature difference and the length of the connecting medium are both
doubled
at the same time, the rate of heat conduction will-----A.
double
B.
equal
C.
D.
halve
remain the same
(32)
Which object has a better emissivity?
A.
B.
C.
D.
a shiny object
a object coated with silver colour
a dull object
a white object
(33) ------- can create some weather conditions.
A.
B.
C.
D.
Heat conduction
Heat convection
Heat radiation
Heat current
(34) ------is a poor thermal insulator.
A.
B.
C.
D.
Copper
Air
Concrete wall
Body tissues
(35) The rate of heat flow is called ---------.
A.
B.
C.
D.
Heat conduction
Amount of heat
Heat current
Heat radiation
(36) The SI unit of total emissive power is------.
A.
B.
C.
D.
watt per meter square
watt per meter per kelvin
watt per meter square per kelvin fourth
joule per second
(37) For a black body the radiation law is represented by the equation------.
A.
B.
C.
D.
H= e σAT4
H= ∆Q/T
ε0 = σT4
∆T= T2- T1