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Thermal Properties of Matter — NEET UG Physics PYQs

272 previous year questions from Thermal Properties of Matter with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

272 questionsPhysicsSolutions on every page
1

A cylindrical rod with one end in a steam chamber and the other end in ice results in melting of 0.1 gram of ice per second. If the rod is replaced by another with half the length

MHT CET Medical 2026 Solution View → 2

A spherical blackbody of radius 10 m is maintained at a temperature T , radiating power P with a peak emission wavelength 5000 Å . If the body is compressed uniformly such that its

MHT CET Medical 2026 Solution View → 3

The rectangular surface area (12 cm 6 cm ) of the black body, at a temperature 127^ C , emits heat energy at the rate of Q units per second. If the length and breadth of the surfac

MHT CET Medical 2026 Solution View → 4

A metal sphere cools at a rate of 2^ C/min when the temperature is 80^ C . If the temperature of the surroundings is 30^ C , then the rate of cooling when its temperature is 50^ C

MHT CET Medical 2026 Solution View → 5

A resistance thermometer has resistance 95 at the ice point and 140 at the steam point. The resistance obtained if the actual temperature is 30^ C is

MHT CET Medical 2026 Solution View → 6

A metal sphere cools from 80^ C to 60^ C in 10 minute. The time taken (in minute) by it to cool from 60^ C to 40^ C if the room temperature is 30^ C , is

MHT CET Medical 2026 Solution View → 7

If the temperature of 5 kg mass of a material of a specific heat capacity 200 J/kg ^ C rises from the 30^ C to 40^ C. The heat received is

MHT CET Medical 2026 Solution View → 8

The initial temperature of a body is 80^ C . If its temperature falls to 64^ C in 5 minutes and in the next 10 minutes to 52^ C , then the temperature of the surroundings is

MHT CET Medical 2026 Solution View → 9

Three very large plates of same area are kept parallel (in vertical plane) and close to each other. They are considered as ideal black surfaces and have very high thermal conductiv

MHT CET Medical 2026 Solution View → 10

Assume that the temperature of the surface of the sun is 5000 K and the surface temperature of another virtual star is 2500 K. The power radiated by a virtual star is 30 times the

MHT CET Medical 2026 Solution View → 11

If the radiant heat absorbed by the body is 75 % of the incident heat and if the coefficient of the reflection is 0.15 , then the coefficient of transmission is

MHT CET Medical 2026 Solution View → 12

Two spherical stars, A and B emit black body radiation. The radius of star A is 400 times that of star B and star A emits power 10^4 times emitted from star B. _A and _B are the wa

MHT CET Medical 2026 Solution View → 13

Coefficient of linear expansion of brass and steel rods are ₁ and ₂ . Lengths of brass and steel rod are l₁ and l₂ respectively. Though the temperature of brass and steel is increa

MHT CET Medical 2026 Solution View → 14

A clock with an iron pendulum keeps the correct time at 14^ C . If the room temperature is 20^ C , the error in a second per day will be nearly (coefficient of linear expansion of

MHT CET Medical 2026 Solution View → 15

Two spherical black bodies have radii R₁ and R₂ . Their surface temperatures are T₁ K and T₂ K respectively. If they radiate the same power, the ratio R₁ R₂ is

MHT CET Medical 2026 Solution View → 16

The rate of dissipation of the heat by a black body at temperature T is Q . The rate of dissipation of heat by ordinary body of the same area at temperature 3T and having emissivit

MHT CET Medical 2026 Solution View → 17

On a new linear scale of temperature (called W scale) the freezing and boiling points of water are 35°W and 235°W respectively. The temperature on the new scale, corresponding to 7

MHT CET Medical 2026 Solution View → 18

The plots of intensity against wavelength for three black bodies at temperatures T₁ , T₂ and T₃ are as shown. The wavelengths are such that

MHT CET Medical 2026 Solution View → 19

The thermal conduction rate ' P_ cond ' of a slab is given by P_ cond = kA(T₁ - T₂) x , where ' x ' is the thickness of the slab and 'A' is the area . The term that represents ther

MHT CET Medical 2026 Solution View → 20

If two temperatures differ by 25 ^ C on Celsius scale, the difference in temperature on Fahrenheit scale is

MHT CET Medical 2026 Solution View → 21

The ratio of emissive power of perfectly black body at 1327 ^ C to that at 527 ^ C is

MHT CET Medical 2026 Solution View → 22

Three spheres P, Q and R, having radii of 2 m, 3 m and 4 m respectively, are coated with lamp-black on their outer surfaces. The wavelengths corresponding to maximum intensity are

MHT CET Medical 2026 Solution View → 23

Assuming the Sun to be a perfectly spherical black body of radius R and is at a temperature T K , then the total radiant power incident on the Earth at a distance r from the sun is

MHT CET Medical 2026 Solution View → 24

The temperature of a metallic sphere of radius R is increased by a small amount T . If the linear coefficient of thermal expansion of the metal is , the approximate increase in the

NEET 2026 Solution View → 25

Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity 2 K while that in the middle has thermal conduc

NEET 2025 Solution View → 26

Two rods one made of copper and other made of steel of the same length and same cross sectional area are joined together. The thermal conductivity of copper and steel are 385 ~J ~s

NEET 2022 Solution View → 27

A cup of coffee cools from 90 ° C to 80 ° C in t   min , when the room temperature is 20 ° C . The time taken by a similar cup of coffee to cool from 80 °

NEET 2021 Solution View → 28

The quantities of heat required to raise the temperature of two solid copper spheres of radii r 1 and r 2 r 1 = 1.5   r 2 through 1   K are in the ratio:

NEET 2020 Solution View → 29

Three stars A ,   B ,   C have surface temperatures T A ,   T B , T C   respectively. Star A appears bluish, star B appears reddish and star C yellowish. Hence,

NEET 2020 Solution View → 30

Psychrometer is used to measure

JIPMER 2019 Solution View → 31

One rod of length 2 m and thermal conductivity 50 unit is attached to another rod of length 1 m and thermal conductivity 100 unit. Temperature of free ends are 70^ C and 50^ C resp

JIPMER 2019 Solution View → 32

A copper rod of 88   c m and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is α C u =

NEET 2019 Solution View → 33

A deep rectangular pond of surface area A , containing water (density = , specific heat capacity =s ), is located in a region where the outside air temperature is a steady value at

NEET 2019 Solution View → 34

An object kept in a large room having air temperature of 25^ C takes 12 minutes to cool from 80^ C to 70^ C . The time taken to cool for the same object from 70^ C to 60^ C would b

NEET 2019 Solution View → 35

1 g of water, of volume 1 ~cm ^3 at 100^ C is converted into steam at same temperature under normal atmospheric pressure = ( 1 10^5 ~Pa ) . The volume of steam formed equals 1671 ~

NEET 2019 Solution View → 36

Calculate radiation power for sphere whose temperature is 227^ C , radius 2 ~m and emissivity 0.8 .

NEET 2019 Solution View → 37

Assertion : Coefficient of thermal conductivity of a metal rod is a function of length of the rod. Reason : Longer the rod, larger is the amount of heat conducted.

NEET 2019 Solution View → 38

How much should the temperature of a brass rod be increased so as to increase its length by 1 % ? (Given, for brass is 0.00002^ C ⁻¹ ).

JIPMER 2018 Solution View → 39

The coefficient of volume expansion of glycerine is 49 10⁻⁵⁰ C ⁻¹ . What is the fractional change in density for a 30^ C rise in temperature?

JIPMER 2018 Solution View → 40

The power radiated by a black body is P and it radiates maximum energy at wavelength, λ 0 . If the temperature of the black body is now changed so that it radiates maximum ene

NEET 2018 Solution View → 41

A sample of 0.1     g of water at 100  o C and normal pressure 1.013 × 10 5  N  m - 2 requires 54     cal of heat energy to convert to s

NEET 2018 Solution View → 42

Two rods A and B of different materials are welded together as shown in figure. Their thermal conductivities are K 1 and K 2 . The thermal conductivity of the composite rod will be

NEET 2017 Solution View → 43

A spherical black body with a radius of 12   cm radiates 450   W power at 500   K . If the radius were halved and the temperature doubled, the power radiated in watt

NEET 2017 Solution View → 44

A body initially at 80^ C cools to 64^ C in 5 ~min and to 52^ C in 10 ~min . The temperature of the surrounding is

NEET 2017 Solution View → 45

A system consist of a cylinder surrounded by a cylindrical shell. A cylinder is a radius R and is made of material of thermal conductivity K , whereas a cylindrical shell has inner

JIPMER 2016 Solution View → 46

A metal rod at a temperature of 145^ C , radiates energy at a rate of 17 W . If its temperature is increased to 273^ C , then it will radiate at the rate of

JIPMER 2016 Solution View → 47

A lead bullet penetrates into a solid object and melts. Assuming that 50 % of its kinetic energy was used to heat it, the initial speed of the bullet is (the initial temperature of

JIPMER 2016 Solution View → 48

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 th

NEET 2016 Solution View → 49

A body cools from a temperature 3 T to 2 T in 10 minutes. The room temperature is T . Assume that Newton's law of cooling is applicable. The temperature of the body at the end of n

NEET 2016 Solution View → 50

A black body is at a temperature of 5760  K. The energy of radiation emitted by the body at wavelength 250  nm is U 1 , at wavelength 500  nm is U 2 and that at 1000

NEET 2016 Solution View → 51

A piece of ice falls from a height h 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

NEET 2016 Solution View → 52

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 s

NEET 2016 Solution View → 53

The temperature of a body is increased from -73^ C to 327^ C . Then the ratio of emissive power is

NEET 2016 Solution View → 54

Assertion : The specific heat of a gas in an adiabatic process is zero and in an isothermal process is infinite. Reason : Specific heat of gas is directly proportional to change of

NEET 2016 Solution View → 55

A slab consists of portions of different materials of same thickness and having the conductivities K₁ and K₂ . The equivalent thermal conductivity of the slab is

JIPMER 2015 Solution View → 56

A lead ball at 30^ C is dropped from a height of 6.2 km . The ball is heated due to the air resistance and it completely melts just before reaching the ground. The molten substance

JIPMER 2015 Solution View → 57

The earth receives solar radiation at a rate of 8.2 ~J ~cm ⁻² ~min ⁻¹ . If the sun radiates as the black bodies, the temperature at the surface of the sun will be (the angle subten

JIPMER 2015 Solution View → 58

Two rigid boxes containing different ideal gases are placed on table. Box A contains one mole of nitrogen at temperature T₀ , while box B contains 1 mole of helium at temperature 7

JIPMER 2015 Solution View → 59

The temperature of the cold junction of thermocouple is 0^ C and the temperature of hot junction is T^ C . The emf is E=16 T-0.04 T^2 V . The inversion temperature T_i is

JIPMER 2015 Solution View → 60

On observing light from three different stars P , Q and R , it was found that intensity of violet colour is maximum in the spectrum of P , the intensity of green colour is maximum

NEET 2015 Solution View → 61

The two ends of a metal rod are maintained at temperatures 100 ° C and 110 ° C . The rate of heat flow in the rod is found to be 4.0 J s - 1 . If the ends are maintained at tempera

NEET 2015 Solution View → 62

If 10 ~g oficeis added to 40 ~g of water at 15^ C , then the temperature ofthemixture is (specificheat of water =4.2 10^3 ~J ~kg ⁻¹ ~K ⁻¹ , Latentheatoffusion of ice =3.36 10^5 ~J

NEET 2015 Solution View → 63

A copper ball 2 ~cm in radius is heated in a furnace to 327^ C . If its emissivity is 0.3 , at what rate does it radiate energy?

NEET 2015 Solution View → 64

Assertion: UV radiation causes photo dissociation of ozone into O ₂ and O , thus causing damage to the stratospheric ozone layer. Reason : Ozone hole is resulting in global warming

NEET 2015 Solution View → 65

Assertion : A hollow metallic closed container with small opening maintained at a high temperature can act as a source of black body radiation. Reason : All metals act as black bod

NEET 2015 Solution View → 66

Assertion : The conductivity of an electrolyte is very low as compared to a metal at room temperature. Reason : The number density of free ions in electrolyte is much smaller as co

NEET 2015 Solution View → 67

50 g ice at 0^ C in insulator vessel, 50 g water of 100^ C is mixed in it, then final temperature of the mixture is (neglect the heat loss)

JIPMER 2014 Solution View → 68

Steam at 100   o C is passed into 20   g of water at 10   o C . When water acquires a temperature of 80 o C , the mass of water present will be: [Take specific heat

NEET 2014 Solution View → 69

Certain quantity of water cools from 70   o C to 60   o C in the first 5 minutes and to 54   o C in the next 5 minutes. The temperature of the surroundings is:

NEET 2014 Solution View → 70

A black body has a wavelength of at temperature 2000 K . Its corresponding wavelength at temperature 3000 K will be

JIPMER 2013 Solution View → 71

An ice-cube of density 900 ~kg / m ^3 is floating in water of density 1000 ~kg / m ^3 . The percentage of volume of ice-cube outside the water is

JIPMER 2013 Solution View → 72

Two metal rods 1 and 2 of same lengths have same temperature difference between their ends. Their thermal conductivities are K₁ and K₂ and crosssectional areas A₁ and A₂ respective

NEET 2013 Solution View → 73

The density of water at 20^ C in 998 ~kg / m ^3 and at a 40^ C 992 ~kg / m ^3 . The cocfficient of volume expansion of water is:

NEET 2013 Solution View → 74

A piece of iron is heated in a flame. If first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is pos

NEET 2013 Solution View → 75

1 ~g of steam is sent into 1 ~g of ice. At thermal equilibrium, the resultant temperature of mixture is

NEET 2013 Solution View → 76

0.1 ~m ^3 of water at 80^ C is mixed with 0.3 ~m ^3 of water at 60^ C . The final temperature of the mixture is

JIPMER 2012 Solution View → 77

The surface temperature of the sun which has maximum energy emission at 500 nm is 6000 K . The temperature of a star which has maximum energy emission at 400 nm will be

JIPMER 2012 Solution View → 78

If the radius of a star is R and it acts as a black body, what would be the temperature of the star, in which the rate of energy production is Q ? ( stands for Stefan's constant.)

NEET 2012 Solution View → 79

Liquid oxygen at 50 ~K is heated to 300 ~K at constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature

NEET 2012 Solution View → 80

A slab of stone of area of 0.36 ~m ^2 and thickness 0.1 ~m is exposed on the lower surface to steam at 100^ C . A block of ice at 0^ C rests on the upper surface of the slab. In on

NEET 2012 Solution View → 81

Two conductors having same width and length, thickness d₁ and d₂ , thermal conductivity K₁ and k₂ are placed one above the another. Find the equivalent thermal conductivity.

NEET 2012 Solution View → 82

Assertion : Maximum air flow due to convection does not occur at the north pole but it occurs at 30^ N Reason : There is maximum temperature difference between equator and 30^ N

NEET 2012 Solution View → 83

The temperature of the sun can be found out by using

JIPMER 2011 Solution View → 84

Emissive and absorptive power of a material at 2000 ~K is 8 and 10 respectively, calculate the emissivity of IBB (Ideal black body)

NEET 2011 Solution View → 85

A black body has a wavelength of at temperature 2000 K . Its corresponding wavelength at temperature 3000 K will be

JIPMER 2010 Solution View → 86

Consider a compound slab consisting of two different materials having equal lengths, thicknesses and thermal conductivities K and 2 K respectively. The equivalent thermal conductiv

JIPMER 2010 Solution View → 87

A cylindrical metallic rod in thermal contact with two reservoirs of heat at its two ends conducts an amount of heat Q in time t. The metallic rod is melted and the material is for

NEET 2010 Solution View → 88

The thermo emf E in volt of a certain thermo-couple is found to vary with temperature difference in ^ C between the two junctions according to the relation E=30 - ^2 15 The neutral

NEET 2010 Solution View → 89

The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of radius r , whose outer surface radiates as a bla

NEET 2010 Solution View → 90

The latent heat of vaporisation of a substance is always

NEET 2010 Solution View → 91

Assertion : Water kept in an open vessel will quickly evaporate on the surface of the moon. Reason : The temperature at the surface of the moon is much higher than boiling point of

NEET 2010 Solution View → 92

A black body at 227^ C radiates heat at the rate of 7 cal cm ⁻² ~s ⁻¹ . At a temperature of 727^ C , the rate of heat radiated in the same units will be

NEET 2009 Solution View → 93

The two ends of a rod of length L and a uniform cross-sectional area A are kept at two temperatures T₁ and T₂ (T₁>T₂ ) . The rate of heat transfer, dQ dt , through the rod in a ste

NEET 2009 Solution View → 94

A black body at 227^ C radiates heat at the rate of 7 cals / cm ^2 ~s . At a temperature of 727^ C , the rate of heat radiated in the same units will be :

NEET 2009 Solution View → 95

The two ends of a rod of length L and a uniform cross-sectional area A are kept at two temperatures T ₁ and T ₂ ( ~T ₁> T ₂ ) . The rate of heat transfer, dQ dt , through the rod i

NEET 2009 Solution View → 96

Light with an energy flux of 18 ~W / cm ^2 falls on a non-reflecting surface at normal incidence. The pressure exerted on the surface is

NEET 2009 Solution View → 97

Assertion : Liquid molecules have greater potential energy at the melting point. Reason: Intermolecular spacing between molecules increases at melting point.

NEET 2009 Solution View → 98

Assertion : When hot water is poured in a beaker of thick glass, the beaker cracks. Reason : Outer surface of the beaker expands suddenly.

NEET 2009 Solution View → 99

Which of the following circular rods, (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

JIPMER 2008 Solution View → 100

Оп a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39^ W and 239^ W respectively. What will be the temperature on

NEET 2008 Solution View → 101

An electric kettle takes 4 ~A current at 220 ~V . How much time will it take to boil 1 ~kg of water from temperature 20^ C ? The temperature of boiling water is 100^ C

NEET 2008 Solution View → 102

On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39^ W and 239^ W respectively. What will be the temperature on

NEET 2008 Solution View → 103

An electric kettle takes 4 ~A current at 220 ~V . How much time will it take to boil 1 ~kg of water from temperature 20^ C ? The temperature of boiling water is 100^ C .

NEET 2008 Solution View → 104

A slab consists of two layers of different materials of the same thickness and having thermal conductivities (K₁ ) and (K₂ ) are connected in series. The equivalent thermal conduct

NEET 2008 Solution View → 105

Which of the following circular rods, (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

JIPMER 2007 Solution View → 106

The temperature of inversion of a thermocouple is 620^ C and the neutral temperature is 300^ C , what is the temperature of cold junction?

JIPMER 2007 Solution View → 107

A black body is at 727^ C . It emits energy at a rate which is proportional to:

NEET 2007 Solution View → 108

Assuming the sun to have a spherical outer surface of radius r , radiating like a black body at temperature t^ C , the power received by a unit surface, (normal to the incident ray

NEET 2007 Solution View → 109

If the cold junction of thermocouple is kept at 0^ C and the hot junction is kept at T^ C , then the relation between neutral temperature (T_n ) and temperature of inversion (T) .

NEET 2007 Solution View → 110

If the temperature of a black body increases from (7^ C ) to (287^ C ) then the rate of energy radiation increases by

NEET 2007 Solution View → 111

Assertion : A hollow metallic closed container maintained at a uniform temperature can act as a source of black body radiation. Reason : All metals act as black bodies.

NEET 2007 Solution View → 112

Assertion : A brass tumbler feels much colder than a wooden tray on a chilly day. Reason : The thermal conductivity of brass is more than the thermal conductivity of wood.

NEET 2007 Solution View → 113

Two rods of same material have same length and area. The heat Q flows through them for 12 minutes when they are joint side by side. If now both the rods are joined in parallel, the

JIPMER 2006 Solution View → 114

A black body at 1227^ C emits radiations with maximum intensity at a wavelength of 5000 Å . If the temperature of the body is increased by 1000^ C , the maximum intensity will be o

NEET 2006 Solution View → 115

Three objects coloured black, gray and white can withstand hostile conditions upto 2800^ C . These objects are thrown into a furnace where each of them attains a temperature of 200

NEET 2006 Solution View → 116

When you make ice cubes, the entropy of water

NEET 2006 Solution View → 117

A body of specific heat 0.2 kcal / kg ^ C is heated through 100^ C . The percentage increase in its mass is

JIPMER 2005 Solution View → 118

The temperature of the black body increases from T to 2 T . The factor by which the rate of emission will increase, is?

JIPMER 2005 Solution View → 119

A steel scale measures the length of a copper wire as 80.0 cm, when both are at 20^ C , the calibration temperature for the scale. What would the scale read for the length of the r

JIPMER 2005 Solution View → 120

Which of the following rods, (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

NEET 2005 Solution View →
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