Physics
Heat and Thermodynamics
Previous Years Questions

## MCQ (More than One Correct Answer)

In the given $P-V$ diagram, a monoatomic gas $\left(\gamma=\frac{5}{3}\right)$ is first compressed adiabatically from state $A$ to state $B$. Then it ...
The filament of a light bulb has surface area 64 mm2 . The filament can be considered as a black body at temperature 2500 K emitting radiation like a ...
A mixture of ideal gas containing 5 moles of monatomic gas and 1 mole of rigid diatomic gas is initially at pressure P0, volume V0, and temperature T0...
One mole of a monatomic ideal gas goes through a thermodynamic cycle, as shown in the volume versus temperature (V-T) diagram. The correct statement(s...
One mole of a monatomic ideal gas undergoes a cyclic process as shown in the figure (where $$V$$ is the volume and $$T$$ is the temperature). Which of...
An ideal monoatomic gas is confined in a horizontal cylinder by a spring loaded piston (as shown in the figure). Initially the gas is at temperature T...
A container of fixed volume has a mixture of one mole of hydrogen and one mole of helium in equilibrium at temperature T. Assuming the gases are ideal...
The figure below shows the variation of specific heat capacity (C) of a solid as a function of temperature (T). The temperature is increased continuou...
One mole of an ideal gas in initial state A undergoes a cyclic process ABCA, as shown in the figure. Its pressure at A is P0. Choose the correct optio...

List I describes thermodynamic processes in four different systems. List II gives the magnitudes (either exactly or as a close approximation) of poss...
The value of $${{{T_R}} \over {{T_0}}}$$ is
The value of $${Q \over {R{T_0}}}$$ is
An ideal gas undergoes a four step cycle as shown in the P-V diagram below. During this cycle, heat is absorbed by the gas in ...
In a thermodynamic process on an ideal monatomic gas, the infinitesimal heat absorbed by the gas is given by T$$\Delta$$X where T is temperature of t...
In a thermodynamic process on an ideal monatomic gas, the infinitesimal heat absorbed by the gas is given by T$$\Delta$$X where T is temperature of t...
One mole of a monatomic ideal gas undergoes four thermodynamic processes as shown schematically in the $$PV$$-diagram below. Among these four processe...
Which one of the following options is the correct combination?
Which of the following options is the only correct representation of a process in which $$\Delta U = \Delta Q - P\Delta V$$?
Which one of the following options correctly represents a thermodynamic process that is used as a correction in the determination of the speed of soun...
A gas is enclosed in a cylinder with a movable frictionless piston. Its initial thermodynamic state at pressure Pi = 105 Pa and volume Vi = 10-3 m3 ch...
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 at 10oC. Now the end P ...
A water cooler of storage capacity 120 litres can cool water at a constant rate of P watts. In a closed circulation system (as shown schematically i...
Parallel rays of light of intensity $$I$$ = 912 Wm–2 are incident on a spherical black body kept in surroundings of temperature 300 K. Take Stefan-Bol...
Consider the partition to be rigidly fixed so that it does not move. When equilibrium is achieved, the final temperature of the gases will be
Now consider the partition to be free to move without friction so that the pressure of gases in both compartments is the same. Then total work done by...
One mole of a monatomic ideal gas is taken along two cyclic processes E $$\to$$ F $$\to$$ G $$\to$$ E and E $$\to$$ F $$\to$$ H $$\to$$ E as shown in ...
Two non-reactive monoatomic ideal gases have their atomic masses in the ratio 2 : 3. The ratio of their partial pressures, when enclosed in a vessel k...
Two rectangular blocks, having identical dimensions, can be arranged in either configuration-I or configuration-II as shown in the figure. One of the ...
Two moles of ideal helium gas are in a rubber balloon at 30oC. The balloon is fully expandable and can be assumed to require no energy in its expansio...
A mixture of 2 moles of helium gas (atomic mass = 4 amu) and 1 mole of argon gas (atomic mass = 40 amu) is kept at 300 K in a container. The ratio of ...
Three very large plates of same area are kept parallel and close to each other. They are considered as ideal black surfaces and have very high thermal...
5.6 liter of helium gas at STP is adiabatically compressed to 0.7 liter. Taking the initial temperature to be T1, the work done in the process is...
One mole of a monatomic gas is taken through a cycle ABCDA as shown in the PV diagram. Column II give the characteristics involved in the cycle. Match...
A real gas behaves like an ideal gas if its

## Numerical

A soft plastic bottle, filled with water of density 1 gm/cc, carries an inverted glass test-tube with some air (ideal gas) trapped as shown in the fig...
A soft plastic bottle, filled with water of density 1 gm/cc, carries an inverted glass test-tube with some air (ideal gas) trapped as shown in the fig...
A small object is placed at the center of a large evacuated hollow spherical container. Assume that the container is maintained at 0 K. At time t = 0,...
A thermally isolated cylindrical closed vessel of height 8 m is kept vertically. It is divided into two equal parts by a diathermic (perfect thermal c...
A spherical bubble inside water has radius R. Take the pressure inside the bubble and the water pressure to be p0. The bubble now gets compressed radi...
A container with 1 kg of water in it is kept in sunlight, which causes the water to get warmer than the surroundings. The average energy per unit time...
Consider one mole of helium gas enclosed in a container at initial pressure P1 and volume V1. It expands isothermally to volume 4V1. After this, the g...
One mole of a monatomic ideal gas undergoes an adiabatic expansion in which its volume becomes eight times its initial value. If the initial temperatu...
A metal is heated in a furnace where a sensor is kept above the metal surface to read the power radiated (P) by the metal. The sensor has a scale that...
Two spherical stars A and B emit blackbody radiation. The radius of A is 400 times that of B and A emits 104 times the power emitted from B. The ratio...
A thermodynamic system is taken from an initial state i with internal energy Ui = 100 J to the final state f along two different paths iaf and ibf, as...
Steel wire of lenght ‘L’ at 40oC is suspended from the ceiling and then a mass ‘m’ is hung from its free end. The wire is cooled down from 40oC to 30o...
Two spherical bodies A (radius 6 cm ) and B (radius 18 cm ) are at temperature T1 and T2, respectively. The maximum intensity in the emission spectrum...
A piece of ice (heat capacity = 2100 J kg-1 oC-1 and latent heat = 3.36 $$\times$$ 105 J kg-1 ) of mass m grams is at - 5 oC at atmospheric pressure...
A diatomic ideal gas is compressed adiabatically $${1 \over {32}}$$ of its initial volume. If the initial temperature of the gas is Ti (in Kelvin) and...
EXAM MAP
Joint Entrance Examination