TNPSC Physics - Heat
Exam Duration: 45 Mins Total Questions : 30
The temperature of boiling water in steam engine may be high because
- (a)
there are dissolved substances in water
- (b)
there is low pressure inside the boiler
- (c)
there is high pressure inside the boiler
- (d)
the fire is at very high temperature
White clothes are cooler than black ones because they
- (a)
absorb all the light that reaches them
- (b)
reflect all the light that reaches them
- (c)
will not allow the light to penetrate
- (d)
cool the sun light completely
Low temperatures (cryogenics) find application in
- (a)
space travel, surgery and magnetic leviation
- (b)
surgery, magnetic leviation and telemetry
- (c)
space travel, surgery and telemetry
- (d)
space travel, magnetic leviation and telemetry
How can boiling point of a liquid be reduced?
- (a)
By adding a solid of lower melting point
- (b)
By dissolving a soluble solid in it
- (c)
By increasing the pressure on the liquid
- (d)
By decreasing the pressure on the liquid
Night are cooler in the deserts than in the plains because
- (a)
sand radiates heat more quickly than the earth
- (b)
the sky remain clear most of the time
- (c)
sand absorbs heat quickly than the earth
- (d)
None of the above
Clothes keep us warm in winter because they
- (a)
supply heat
- (b)
do not radiate heat
- (c)
prevent air from contacting the body
- (d)
prevent the heat of the body from escaping
The water from a hand-pump is warm in winter because
- (a)
our body is cold in winter and water appears to be warm
- (b)
the temperature inside the earth is higher than the atmospheric temperature
- (c)
the pumping process causes friction which warms up the water
- (d)
inside water comes out and absorbs heat from the environment
A hollow sphere of radius R, a hollow cube of side R and thin circular plate of radius R made up of the same material, are all heated to 20\(^{0}\) C above room temperature. When left to cool in the room, which of them will reach the room temperature first?
- (a)
Circular plate
- (b)
Cube
- (c)
Sphere
- (d)
All of them will reach the room temperature at the same time
Woollen clothes keep the body warm because
- (a)
wool absorbs radiant heat from outer objects
- (b)
wool increases the temperature of the body
- (c)
wool is the bad conductor of the heat so it does not allow heat to flow out of the body
- (d)
wool rejects heat from outer objects
The temperature of a gas is measured with a
- (a)
gas thermometer
- (b)
platinum resistance thermometer
- (c)
vapour pressure thermometer
- (d)
pyrometer
Consider the following statements
1. Heat can be reflected by mirror.
2. Heat is a form of energy.
3. Heat cannot pass through vaccum.
4. Heat is an electromagnetic radiation.
Which of the statements given above are correct?
- (a)
1, 2, and 3
- (b)
1, 3 and 4
- (c)
2 and 4
- (d)
1, 2, 3 and 4
The first law of thermodynamics is concerned with the conservation of
- (a)
energy
- (b)
number of molecules
- (c)
number of moles
- (d)
temperature
The boiling point of liquid is
- (a)
increases with increase in pressure
- (b)
affected by addition of soluble solid
- (c)
Both (a) and (b)
- (d)
None of the above
Match the following lists
List I | List II |
A. In an isothermal process | 1. Temperature remains constant |
B. In an adiabatic process | 2. Volume remains constant |
C. In an isobaric process | 3. Heat content remains constant |
D. In an isochoric process | 4. Pressure remains constant |
- (a)
A B C D 1 2 3 4 - (b)
A B C D 1 3 4 2 - (c)
A B C D 4 3 2 1 - (d)
A B C D 3 2 1 4
The temperature at which the vapour pressure of a liquid becomes equal to the external (atmospheric) pressure is its
- (a)
inversion point
- (b)
melting point
- (c)
boiling point
- (d)
None of these
Heat capacity of substance is infinite. It means
- (a)
infinite heat is taken in
- (b)
infinite heat is given out
- (c)
no change in temperature whether heat is taken in or given out
- (d)
All of the above
A gas has
- (a)
two specific heat
- (b)
one specific heat
- (c)
three specific heat
- (d)
infinite no of values of specific heat
The product of the pressure and volume of an ideal gas is
- (a)
directly proportional to its temperature
- (b)
inversely proportional to its temperature
- (c)
a constant
- (d)
approximately equal to the universal gas constant
A gas behaves as an ideal gas more closely at
- (a)
low pressure and high temperature
- (b)
high pressure and high temperature
- (c)
low pressure and low temperature
- (d)
high pressure and low temperature
The pressure exerted on the walls of the container by a gas is due to the fact that the gas moleculs
- (a)
stick to the walls
- (b)
lose their kinetic energy
- (c)
change their momenta due to collision with the walls
- (d)
are accelerated towards the walls
The specific heat of a gas at constant pressure is greater than the specific heat at constant volume because
- (a)
work is done in the expansion of the gas at constant volume
- (b)
work is done in the expansion of the gas at constant pressure
- (c)
the molecular collision increases at constant pressure
- (d)
the attraction between the molecules increases at constant pressure
When a temperature is gradually decreased, the specific heat of substance is
- (a)
increased
- (b)
decreased
- (c)
remain unchanged
- (d)
None of the above
Which one of the following substances has greatest specific heat?
- (a)
Water
- (b)
Mercury
- (c)
Iron
- (d)
Copper
Dry ice is
- (a)
ice cube
- (b)
sodium chloride
- (c)
liquid nitrogen
- (d)
solid carbon dioxide
When we rub our palms they gets heated but to a maximum temperature because
- (a)
heat is absorbed by our palm
- (b)
heat is lost in the environment
- (c)
produced of heat is stopped
- (d)
None of the above
Which of the following has maximum specific heat?
- (a)
Water
- (b)
Alcohol
- (c)
Glycerine
- (d)
Oil
Mud houses are cooler in summer and warmer in winter because
- (a)
Mud is superconductor of heat
- (b)
Mud is good conductor of heat
- (c)
Mud is bad conductor of heat
- (d)
None of the above
When red glass is heated in dark room it will seem?
- (a)
Green
- (b)
Purple
- (c)
Black
- (d)
Yellow
Absorptive power ital of a body is defined as
- (a)
a= energy incident/energy absorbed
- (b)
a= energy absorbed/energy emitted
- (c)
a= energy emitted/energy absorbed
- (d)
a= energy absorbed/energy incident
Which among the following materials were used for minting coins during the rule of the Mauryas?
- (a)
Gold and Silver
- (b)
Silver and Copper
- (c)
Copper and Bronze
- (d)
Gold and Copper