9th Class Physics Chapter No.9 Past Paper MCQs
HAMZA SCIENCE ACADEMY
Physics MCQs Test Class 9th
Chapter # 9
TRANSFER OF HEAT
1. In solids, heat is transferred by:
(A)
Conduction
(B)
Convection
(C)
Radiation
(D) Absorption
2. What happens to the thermal conductivity of a wall if its
thickness is doubled?
(A)
Becomes double
(B)
Remains the same
(C) Becomes half
(D) Becomes one fourth
3.
In
gases, heat is mainly transferred by:
(A)
Molecular collision
(B)
Conduction
(C)
Convection
(D) Radiation
4. False ceiling is done to:
(A)
Lower the heat of ceiling
(B)
Keep the roof clean
(C)
Cool the room
(D) Insulate the ceiling
5.
Rooms
are heated using gas heaters by:
(A)
Conduction only
(B)
Both conduction and radiation
(C)
Radiation only
(D) Convection only
6.
The
ways by which transfer of heat takes place are:
(A)
1
(B)
4
(C)
2
(D) 3
7. Thermal conductivity of silver is____________ Wmˉ1Kˉ1
(A)
0.08Wmˉ1Kˉ1
(B)
1.7 Wmˉ1Kˉ1
(C)
0.2 Wmˉ1Kˉ1
(D)
0.59 Wmˉ1Kˉ1
8. Thermal conductivity of rubber is___________
Wmˉ1Kˉ1
(A)
245
(B)
105
(C)
400
(D) 430
9.
Example
of a bad conductor is:
(A)
Gold
(B)
Iron
(C)
Wood
(D) Graphite
10. Heat transfers through fluids by the method called:
(A)
Radiation
(B)
Conduction
(C)
Convection
(D) Absorption
11. Reason of glider to remain in air is:
(A)
Power
(B)
Conduction
(C)
Radiation
(D) Convection
12. The major source of heat energy is:
(A)
Moon
(B)
Earth
(C)
Nuclear fuels
(D) Sun
13. Metals are good conductors of heat due to:
(A)
Free electrons
(B)
Big size of their molecules
(C)
Small size of their
molecules
(D) Rapid vibrations of their atoms
14. The thermal conductivity of a dry
air is _______ Wm-1K-1 .
(A)
0.08
(B)
0.03
(C)
0.02
(D) 0.026
15. Land breeze and sea breeze are the result of:
(A)
Conduction
(B)
Convection
(C)
Radiation
(D) Absorption
16. A Leslie’s cube has faces:
(A)
Two
(B)
Four
(C)
Six
(D) Eight
17.
Which
of the following is a good radiator of heat?
(A)
A shining silvered surface
(B)
A dull black surface
(C)
A white surface
(D) A green colored surface
18. Which color is a good absorber?
(A) White
(B) Black
(C) Shiny
(D)
Colored
19. Warm clothes for winter season are:
(A)
Woollen
(B)
Silky
(C)
Plastic
(D) Cotton
20.
Land breeze
blows from:
(A)
Sea to land during night
(B)
Sea to land during the day
(C)
Land to sea during night
(D) Land to sea during the day
21. In liquids, heat is mainly transferred by:
(A)
Free electrons
(B)
Conduction
(C)
Radiation
(D) Convection
22. Thermal conductivity of brick is:
(A)
0.6wm-1k-1
(B)
0.2wm-1k-1
(C)
0.8wm-1k-1
(D) 1.7wm-1k-1
23. The unit of thermal conductivity
is:
(A) WmK
(B) Wm-1K-1
(C) WmK-1
(D) Wm2K-1
24. Unit of rate of thermal energy
is:
(A) Kelvin
(B) Joule per second
(C) Joule
(D) Second per joule
25. Which of the following is a bad
conductor?
(A) Gold
(B) Wood
(C) Iron
(D) None of these
26. The
unit of rate of change of thermal energy is:
(A)
(B) J
(C) K
(D)
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