Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 83

MEDIUM

NEET

IMPORTANT

Earn 100

The rate of emission of energy by a unit area of a body is $10$ watt and that of sun is $10^{6}$ watt. The emissive power of the body is $0.1 .$ If the temperature of the sun is $6000 K,$ then the temperature of the body will be-

100% studentsanswered this correctly

Important Questions on Heat Transfer

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 84

The ratio of masses of two copper spheres of identical surfaces is

8 : 1 .

If their temperatures are

2000 K

and

1000 K

, respectively, then the ratio of energies radiated per second by the two is,

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 85

A solid body is heated upto very high temperatures. As we go on heating, its brightness increases and it appears white at the end. The sequene of the colour observed as the temperature of the body increases will be-

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 86

The effective area of a black body is

0.1 m^{2}

and its temperature is

100 K .

The amount of radiations emitted by it per min is -

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 87

What is the energy of emitted radiation from Sun when the temperature is doubled

HARD

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 88

Newton's law of cooling is a special case of

EASY

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 89

A hot liquid is kept in a big room. Its temperature is plotted as a function of time. Which of the following curves may represent the plot?

Question Image

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 90

A body takes

4

minutes to cool from

100 ° C

to

70 ° C .

To cool from

70 ° C

to

40 ° C

it will take-(room temperature is

15 ° C

)

MEDIUM

NEET

IMPORTANT

Alpha Question Bank for Medical: Physics>Chapter 16 - Heat Transfer>Exercise-1>Q 91

A cup of tea cools from

80 ° C

to

60 ° C

in one minute. The ambient temperature is

30 ° C .

In cooling from

60 ° C

to

50 ° C

it will take-