Question 1 : Assertion: The isothermal curves intersect each other at a certain point. Reason: The isothermal changes takes place rapidly, so the thermal curves have very little slope.

Question 2 : Only a part heat energy absorbed can be converted to work by heat engine because:

Question 3 : Assertion: Reversible systems are difficult to find in the real world. Reason: Most processes are dissipative in nature.

Question 6 : A reversible engine takes heat from a reservoir at $527 ^o$ C and gives out heat to a sink at $127^o$ C. How many Joules/s must it take from the reservoir to perform useful mechanical work at the rate of $750 \ W$?

Question 7 : A monoatomic gas at pressure $P_1$ and volume $V_1$ is compressed adiabatically to $\displaystyle \frac{1}{8}$th of its original volume. What is the final pressure of the gas

Question 8 : For adiabatic expansion of perfect monoatomic gas , when voulme increases by $ 24\%$ ,what is the percentage decrease in pressure ?

Question 10 : During an adiabatic change the density becomes $\cfrac{1}{16}th$ of the initial value, then $\cfrac{P_{1}}{P_{2}}$ is : $\left ( \gamma =1.5 \right )$<br>

Question 11 : An automobile engine absorbs $1600 \ J$ of heat from a hot reservoir and expel $1000\ J$ to a cold reservoir in each cycle. What maximum work is done in each cycle?

Question 12 : For an adiabatic expansion of a perfect gas, the value of $\Delta P/P$ is equal to:

Question 13 : Compressed air in the tube of a wheel of a cycle at normal temperature suddenly starts coming out of the puncture. The air inside

Question 15 : A series combination of two Carnots engines operate between the temperatures of $180^0C$ and $20^0C$. If the engines produce equal amount of work,then what is the intermediate temperature(In $^0C$)?

Question 16 : An ideal monoatomic gas at&#160;$\displaystyle { 27 }^{ \circ &#160;}C$ is compressed adiabatically to $8/27$ times of its present volume. The increase in temperature of the gas is:

Question 17 : An iron block of mass $2\;kg$, falls from a height of $10m$. After colliding with the ground it loses $25\%$ energy to surroundings and rest is gained as heat. Then find the temperature rise of the block. (Take sp. heat of iron $470\;J/kg^{\circ}C$)<br/>

Question 18 : When 100 J of heat is given to an ideal gas it expands from 200 $cm^3$ to 400 $ cm^3$ at a constant pressure of $3 \times 10^5$ Pa. Then calculate the&#160;change in internal energy of the gas :$R=\left [ \dfrac{25}{3}J/mol-k \right ]$<br/>

Question 19 : In a particular experiment, a gas undergoes adiabatic expansion satisfying the equation $\displaystyle { VT }^{ 3 }$=constant. The ration of specific heats, $\displaystyle Y $ is:

Question 20 : $146 \ kJ$ 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 21 : At $\displaystyle&#160;27^{ o }C$ a gas ($\displaystyle \gamma ={ 5 }/{ 3 }$) is compressed suddenly so that its pressure becomes $\dfrac{1}{8}$ of the original pressure. Final temperature of gas would be:

Question 22 : A sound wave passing through air at $NTP$ produces a pressure of $0.001\ dyne/cm^2$ during a compression. The corresponding change in temperature (given $\gamma = 1.5$ and assume gas to be ideal) is&#160;

Question 23 : Water of mass $m_2$ = 1 kg is contained in a copper calorimeter of mass&#160;$m_1$&#160;&#160;= 1 kg. Their common temperature&#160;t = $10^{0}C$. Now a piece of ice of mass&#160;$m_3$&#160;&#160;= 2 kg and temperature is $-11^{0}C$&#160;dropped into the calorimeter.&#160;Neglecting any heat loss, the final temperature of system is. [specific heat of copper = 0.1 Kcal/ kg$^{0}C$, specific&#160;heat of water = 1 Kcal/kg$^{0}C$, specific heat of ice = 0.5 Kcal/kg$^{0}C$, latent heat of fusion of ice = 78.7 Kcal/kg]

Question 24 : Piston cylinder device initially contains $0.5 m^3$ of nitrogen gas at $400 kPa$ and $27^o$C. An electric heater within the device is at turned on and is allowed to pass a current of $2 A$ for $5 \ min$ from a $120 V$ source. Nitrogen expands at constant pressure and a heat loss of $2800 J$ occurs during the process.<br/>$R = \dfrac{25}{3} kJ/kmol-K$The final temperature of nitrogen is:

Question 26 : A gas is compressed from a volume of $2 m^3$ to a volume of $1 m^3$ at a constant pressure of $100 N/m^2$. Then it is heated at constant volume by supplying $150 \ J$ of energy. As a result, the internal energy of the gas :

Question 27 : Two samples of gases 1 and 2 are initially kept in the same state. Sample 1 is expanded through an isothermal process whereas sample 2 through an adiabatic process up to the same final volume. Let $P_1$ and $P_2$ be the final pressure of the samples 1 and 2 respectively then

Question 28 : Assertion: Suppose some reaction takes place in a container which has a movable side,then if it is known that for that particular reaction its entropy change is negative then we can necessarily say that that reaction is not possible. Reason: For any process to undergo,its entropy change must be positive.

Question 29 : 4.0 kg of a gas occupies 22 . 4 litres at NTP. The specific heat capacity of the gas at constant volume is 5.0 $J K ^ { - 1 }$ $m o l ^ { - 1 }$ If the speed of sound in this gas at NTP is 952 $m s ^ { - 1 }$ then the heat capacity at constant pressure is (Take gas constant R = 8.3 $J K ^ { - 1 }$ $m o l ^ { - 1 }$

Question 30 : 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