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Which temperature scale have only positive temperatures?

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Important Questions on Heat and Thermodynamics

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Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

Coefficient of linear expansion of brass and steel rods are

α_{1}

and

α_{2}

. Lengths of brass and steel rods are

l_{1}

and

l_{2}

, respectively. If

(l_{2} - l_{1})

is maintained the same at all temperatures, which one of the following relations holds good?

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A thin paper cup filled with water does not catch fire when placed over a flame. This is because

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A body cools from

{50.0}^{o} C

{49.9}^{o} C

5 s.

How long will it take to cool from

{40.0}^{o} C

{39.9}^{o} C

? Assume the temperature of surroundings to be

{30.0}^{o} C

and Newton's law of cooling to be valid

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A spring - block system is resting on a frictionless floor as shown in the figure. The spring constant is

2.0 N m^{- 1}

and the mass of the block is

2 .0 kg

. Ignore the mass of the spring. Initially the spring is in an unstretched condition. Another block of mass

1.0 kg

moving with a speed of

2 .0 m s^{- 1}

collides elastically with the first block. The collision is such that the

2.0 kg

block does not hit the wall. The distance, in metres, between the two blocks when the spring returns to its unstretched position for the first time after the collision is _________.

Question Image

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A faulty thermometer reads

5 ° C

in melting ice and

95 ° C

in steam. The correct temperature on absolute scale will be ______

K

when the faulty thermometer reads

41 ° C

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

An unknown metal of mass

192 g

heated to a temperature of

100 ° C

was immersed into a brass calorimeter of mass

128 g

containing

240 g

of water at a temperature of

8.4 ° C .

Calculate the specific heat of the unknown metal if water temperature stabilizes at

21.5 ° C .

(

Specific heat of brass is

394 J {kg}^{- 1} K^{- 1})

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

The SI unit of mechanical equivalent of heat is

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A copper ball of mass

100 g

is at a temperature

T

. It is dropped in a copper calorimeter of mass

100 g,

filled with

170 g

of water at room temperature. Subsequently, the temperature of the system is found to be

75 ° C

T

is given by:
(Given: room temperature

= 30 ° C

, specific heat of copper

= 0.1 cal g^{- 1} ° C^{- 1}

)

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

On a temperature scale '

X

', the boiling point of water is

65 ° X

and the freezing point is

- 15 ° X

. Assuming that the

X

scale is linear. The equivalent temperature corresponding to

- 95 ° X

on the Fahrenheit scale would be

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

Solar energy is incident normally on the earth's surface at the rate of about

1 .4 kW m^{- 2}

. The distance between the earth and the sun is

1 .5 \times 10^{11} m

. Energy

(E)

and mass

(m)

are related by the Einstein equation,

E = m c^{2}

where

c = (3 \times 10^{8} m s^{- 1})

is the speed of light in free space. The decrease in the mass of the sun is

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

The value of coefficient of volume expansion of glycerin is

5 \times 10^{- 4} K^{- 1}

. The magnitude of fractional change in the density of glycerin for a rise of

40^{o} C

in its temperature is:

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this?

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on

T a s T^{q}

. A good estimate for q is:

HARD

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

The ends Q and R of two thin wires, PQ and RS, are soldered (joined) together. Initially each of the wires has a length of

1 m

10 ° C .

Now the end P is maintained at

10 ° C,

while the end S is heated and maintained at

400 ° C .

The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ is twice that of the wire RS and the coefficient of linear thermal expansion of PQ is

1.2 \times 10^{- 5} K^{- 1},

the change in length of the wire PQ is

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is at

100^{o} C

, while the other one is at

0^{o} C

. If the two bodies are brought into contact, then assuming no heat loss, the final common temperature is

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

N molecules each of mass m of a gas

A

and

2 N

molecules each of mass

2 m

of gas

B

are contained in the same vessel which is maintained at temperature

T

. The mean square velocity of molecules of

B

type is

v^{2}

and the mean square rectangular component of the velocity of

A

type is denoted by

ω^{2}

. Then the value of

ω^{2} / v^{2}

is -

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

An aluminium piece of mass

50 g

initially at

300 ° C

is dipped quickly and taken out of

1 kg

of water, initially at

30 ° C .

If the temperature of the aluminium piece immediately after being taken out of the water is found to be

160 ° C,

what is the temperature of the water? Then, specific heat capacities of aluminium and water are

900 J {kg}^{- 1} K^{- 1}

and

4200 J {kg}^{- 1} K^{- 1}

, respectively.

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

Ice is used in a cooler in order to cool its contents. Which of the following will speed up the cooling process?

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

The graph between two temperature scales $P$ and $Q$ is shown in the figure. Between upper fixed point and lower fixed point there are $150$ equal divisions of scale $P$ and $100$ divisions on scale $Q$ . The relationship for conversion between the two scales is given by :

Question Image .

HARD

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Temperature

A certain liquid has a melting point of

- 50 ° C

and a boiling point of

150 ° C

. A thermometer is designed with this liquid and its melting and boiling points are designated at

0 ° L

and

100 ° L

. The melting and boiling points of water on this scale are

Which temperature scale have only positive temperatures?

Important Questions on Heat and Thermodynamics

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