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Question (1)

QN0035791

The value of coefficient of volume expansion of glycerine is . The fractional change in the density of glycerine for a rise of in its temperature, is:

(A)
0.020
(B)
0.025
(C)
0.010
(D)
0.015

Correct Answer: A

Explanation:

Coefficient of volume expansion

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Question (2)

QN0035792

Coefficient of linear expansion of brass and steel rods are and . Lengths of brass and steel rods are and respectively. If is maintained same at all temperatures, which one of the following relations holds good?

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

From question, is maintained same at all temperatures hence change in length for both rods should be same

i.e.,

As we know, coefficient of linear expansion,

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Question (3)

QN0035793

A black body is at a temperature of . The energy of radiation emitted by the body at wavelength is , at wavelength is and that at is . Wien's constant, . Which of the following is correct?

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

According to wein's displacement law, maximum amount of emitted radiation corresponding to

From the graph

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Question (4)

QN0035794

A piece of ice falls from a height so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of is : [Latent heat of ice is and ]

(A)
(B)
(C)
(D)
.

Correct Answer: C

Explanation:

According to question only one-quarter of the heat produced by falling piece of ice is absorbed in the melting

of ice. i.e.,

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Question (5)

QN0035795

Two rods and of different materials are welded together as shown in figure. Their thermal conductivities are and . The thermal conductivity of the composite rod will be:

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

Heat current

Hence equivalent thermal conductivities for two rods of equal area is given by

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Question (6)

QN0035796

A spherical black body with a radius of radiates 450 watt power at . If the radius were halved and the temperature doubled, the power radiated in watt would be :

(A)
450
(B)
1000
(C)
1800
(D)
225

Correct Answer: C

Explanation:

Given

and watt Rate of power loss

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Question (7)

QN0035797

An external pressure is applied on a cube at so that it is equally compressed from all sides. is the bulk modulus of the material of the cube and is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by :

(A)
(B)
(C)
(D)

Correct Answer: C

Explanation:

As we know, Bulk modulus

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Question (8)

QN0035798

The power radiated by a black body is and it radiates maximum energy at wavelength, . If the temperature of the black body is now changed so that it radiates maximum energy at wavelength , the power radiated by it becomes . The value of is

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

From Wein's law constant

i.e.,

Power radiated

So,

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Question (9)

QN0035799

A copper rod of and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is : and

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

Since, change in length is independent of temperature

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Question (10)

QN0035800

The quantities of heat required to raise the temperature of two solid copper spheres of radii and through are in the ratio :

(A)
(B)
(C)
(D)

Correct Answer: D

Explanation:

Heat supplied,

or

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Question (1)

The value of coefficient of volume expansion of glycerine is . The fractional change in the density of glycerine for a rise of in its temperature, is:

Explanation:

Link:

Question (2)

Coefficient of linear expansion of brass and steel rods are and . Lengths of brass and steel rods are and respectively. If is maintained same at all temperatures, which one of the following relations holds good?

Explanation:

Link:

Question (3)

A black body is at a temperature of . The energy of radiation emitted by the body at wavelength is , at wavelength is and that at is . Wien's constant, . Which of the following is correct?

Explanation:

Link:

Question (4)

A piece of ice falls from a height so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of is : [Latent heat of ice is and ]

Explanation:

Link:

Question (5)

Two rods and of different materials are welded together as shown in figure. Their thermal conductivities are and . The thermal conductivity of the composite rod will be:

Explanation:

Link:

Question (6)

A spherical black body with a radius of radiates 450 watt power at . If the radius were halved and the temperature doubled, the power radiated in watt would be :

Explanation:

Link:

Question (7)

An external pressure is applied on a cube at so that it is equally compressed from all sides. is the bulk modulus of the material of the cube and is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by :

Explanation:

Link:

Question (8)

The power radiated by a black body is and it radiates maximum energy at wavelength, . If the temperature of the black body is now changed so that it radiates maximum energy at wavelength , the power radiated by it becomes . The value of is

Explanation:

Link:

Question (9)

A copper rod of and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is : and

Explanation:

Link:

Question (10)

The quantities of heat required to raise the temperature of two solid copper spheres of radii and through are in the ratio :

Explanation:

Link:

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