Question 1 :
In carnot cycle to increase efficiency which of the following parameter need to be changed?

Question 2 :
Work done in an adiabatic process between a given pair of end states depends on

Question 3 :
In a heat engine, heat energy is converted into mechanical energy.&#160;<br/>

Question 5 :
In an adiabatic expansion, the temperature of 5 moles of gas $\gamma =1.5$ falls from $87^{0}C$ to $27^{0}C$, then the work done is<br>

Question 6 :
For an adiabatic process the relation between V&#160;and T is given by&#160;<br/>

Question 7 :
Which of the following laws of thermodynamics&#160;leads to the inference that it is difficult to convert&#160;whole of heat into work :<br/>

Question 10 :
The process in which the internal energy of the&#160;system remains constant is :<br/>

Question 12 :
In a reversible process, system goes from an initial state A to a final state B. Which of the following is true?

Question 13 :
By opening the door of a refrigerator which is&#160;inside a room, the temperature of room ____________.

Question 14 :
Which of the following is true in the case of an&#160;adiabatic process where $\gamma =C_{p}/C_{v}$?<br/>

Question 15 :
Of the following thermodynamic processes, the thermodynamic process in which internal energy of a gas remains constant is

Question 16 :
Diffusion of a gas in a room is not reversible because:

Question 18 :
A gas expands adiabatically at constant pressure, such that its temperature $T \propto \frac{1}{\sqrt{V}}$. The value of $C_p / C_V$ of the gas is:

Question 22 :
The heat energy required to raise the temperature of _______ of a substance through ________ is called its specific heat capacity.

Question 23 :
The ratio of densities of two substances is 2 : 3 and that of specific heats is 1 : 2. The ratio of thermal capacities per unit volume is<br>

Question 24 :
Half mole of an ideal monoatomic gas is heated at constant pressure of 1 atm from $20^oC$ to $90^oC$. Work done by gas close to : (Gas constant R = 8.31 J / mol. K)

Question 26 :
Assertion: Internal energy of a system is an extensive property. Reason: The internal energy of a system depends upon the amount and physical state of the substance.

Question 27 :
150 J of heat has been added to the gas When 1 kg of ice at $0 ^ { \circ } \mathrm { C }$ melts to water at $0 ^ { \circ } \mathrm { C }$ the resulting change in its entropy latent heat of ice to be $80 \mathrm { cal } / ^ { \circ } \mathrm { C }$ is

Question 29 :
An automobile engine absorbs $1600 \ J$ of heat from a hot reservoir and expel $1000\ J$ to a cold reservoir in each cycle. What is the power output of engine if it operates at $200$ cycle per minute?

Question 30 :
An ideal heat engine working between temperature T and T has an efficiency&#160;$\eta $, the new efficiency if both the source and sink temperature are doubled, will be

Question 31 :
Efficiency of a heat engine whose sink is at a temperature of $300 \ K$ is $40$%. To increase the efficiency to $60$%, keeping the sink temperature constant, the source temperature must be increased by :<br/>

Question 32 :
$146 \ kJ$ work is performed in order to compress 1 kilomole of gas adiabatically and in this process&#160;the temperature of the gas increases by&#160;$7^{o}C $. The gas is:<br/>(Take $R\; =\; 8.3 &#160;J mole^{-1}K^{-1} $)&#160;<br/>

Question 33 :
Heat is supplied to a diatomic gas at constant pressure. The ratio between heat energy supplied and&#160;work done is:( $\gamma$&#160;for diatomic gas $=\dfrac{7}{5}$)

Question 34 :
A gas in a cylinder held at a constant pressure of $1.7\,\times\, 10^{5}$ Pa and is cooled and compressed from $1.20\, m^{3}\, to\,&#160;0.8\, m^{3}$. The internal energy of the gas decreses by $1.1\, \times\, 10^{5}$ J.<br/>Does it matter whether or not the gas is ideal? Mark 1-&gt;Yes and 0-&gt;No

Question 35 :
A monoatomic ideal gas, initially at temperature $T_1$, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature $T_2$ by releasing the piston suddenly. If $L_1$ and $L_2$ are lengths of gas column before and after expansion respectively, then $\displaystyle \dfrac{T_1}{T_2}$ is given by

Question 36 :
When you approach the fire, you feel heat on your body. Which of the following mode of heat transfer&#160;is involved in this ?

Question 37 :
Bunty mixed 440 gm of ice at $0^{\circ}C$ with 540 gm of water&#160;at $80^{\circ} C$ in a bowl. Then what would remain after sometime in the bowl?<br/>

Question 38 :
Two copper spheres of radii $6 cm$ and $12 cm$ respectively are suspended in an evacuated enclosure. Each of them are at a temperature $15^0 C$ above the surroundings. The ratio of their rate of loss of heat is ___________.

Question 39 :
In convection process rate of heat transfer is compared in the option between gas and liquid,choose the correct statement

Question 40 :
"The rate of loss of heat $-dQ/dt$ of the body is directly proportional to tohe temperature difference $\triangle \,T=(T_2-T_1)$ of the body and surrounding ".This statements is

Question 41 :
If we place our hand below a lighted electric&#160;bulb. We feel warmer because of :

Question 44 :
I: A sphere&#160;II: A cube&#160;III: A thin circular plate;&#160;All&#160;made of the same material having the same mass&#160;are initially heated to $200$ <br> $^{0}$C. Identify the order in&#160;which the objects cool faster when left in air at&#160;room temperature :

Question 46 :
Two spheres of the same size are made of the same metal, but one is hollow but the other is solid.When , they are heated to the same temperature then

Question 50 :
An aluminium&#160;block of 2m mass&#160;and an iron&#160;block of m mass,each absorbs the same amount of heat, and&#160;both blocks remain solid. If the specific heat of aluminium is twice the specific heat of iron, then find out the correct statement?

Question 51 :
Steam at $100^{\circ}C$ is passed into $1.1\ kg$ of water contained in a calorimeter of water equivalent $0.02\ kg$ at $15^{\circ}C$ till the temperature of the calorimeter and its contents rises to $80^{\circ}C$. The mass of the steam condensed in kilograms is<br>

Question 52 :
An iron ring measuring $15.00\;cm$ in diameter is to be shrunk on a pulley which is $15.05\;cm$ in diameter. All measurements refer to the room temperature $20^{\circ}C$. To what minimum temperature should the ring be heated to make the job possible? Calculate the strain developed in the ring when it comes to the room temperature. Coefficient of linear expansion of iron $=12\times10^{-6}/^\circ C$.

Question 53 :
Radiation emitted from a radioactive element, of half life period of $30$ min, are measured by a Geigar - Mullar counter. The count rate of the sample reduces to $ 5$ disintegrations /sec. in $2hrs$. then the initial count rate in disintegration/sec is :-

Question 54 :
A solid body X of heat capacity C is kept in an atmosphere whose temperature is $T_A=300$K. At time $t=0$ the temperature of X is $T_0=400$K. It cools according to Newton's law of cooling. At time $t_1$, its temperature is found to be $350$K.<br>At this time $(t_1)$, the body X is connected to a large body Y at atmospheric temperature $T_A$, through a conducting rod of length L, cross-sectional area A and thermal conductivity K. The heat capacity of Y is so large that any variation in its temperature may be neglected. The cross-sectional area A of the connecting rod is small compared to the surface area of X. Find the temperature of X at time $t=3t_1$.<br>

Question 55 :
Two bodies $A$ and $B$ have thermal emissivities&#160;of $0.01$ and $0.81$ respectively. The outer&#160;surface areas of the two bodies are the&#160;same and&#160;radiate energy at the&#160;same rate. The wavelength $\lambda&#160;_{B}$, corresponding&#160;to the maximum spectral radiancy in the&#160;radiation from $B$, is shifted from the wavelength&#160;corresponding to the maximum spectral&#160;radiancy in the radiation from $A$ by $1.00\mu&#160;m$. If the temperature of $A$ is $5802$ K,