Correct4
Incorrect-1
Heat given to a body which raises its temperature by {tex} 1 ^ { \circ } \mathrm { C } {/tex} is
water equivalent
thermal capacity
specific heat
temperature gradient.
Correct4
Incorrect-1
Which statement is incorrect?
all reversible cycles have same efficiency
reversible cycle has more efficiency than an irreversible one
Carnot cycle is a reversible one
Carnot cycle has the maximum efficiency in all cycles.
Correct4
Incorrect-1
Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will
increase
decrease
remain same
decrease for some, while increase for others.
Correct4
Incorrect-1
At what temperature is the r.m.s. velocity of a hydrogen molecule equal to that of an oxygen molecule at {tex} 47 ^ { \circ } \mathrm { C } ? {/tex}
{tex} 80 \mathrm {\ K } {/tex}
{tex} - 73 \mathrm {\ K } {/tex}
{tex} 3 \mathrm {\ K } {/tex}
{tex} 20 \mathrm {\ K } {/tex}
Correct4
Incorrect-1
Even Carnot engine cannot give {tex} 100 \% {/tex} efficiency because we cannot
prevent radiation
find ideal sources
reach absolute zero temperature
eliminate friction.
Correct4
Incorrect-1
{tex}1{/tex} mole of a gas with {tex} \gamma = 7 / 5 {/tex} is mixed with {tex}1{/tex} mole of a gas with {tex} \gamma = 5 / 3 , {/tex} then the value of {tex} \gamma {/tex} for the resulting mixture is
{tex} 7 / 5 {/tex}
{tex} 2 / 5 {/tex}
{tex} 24 / 16 {/tex}
{tex} 12 / 7 {/tex}
Correct4
Incorrect-1
"Heat cannot by itself flow from a body at lower temperature to a body at higher temperature" is a statement or consequence of
second law of thermodynamics
conservation of momentum
conservation of mass
first law of thermodynamics.
Correct4
Incorrect-1
During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio {tex} C _ { P } / C _ { V } {/tex} for the gas is
{tex} 4 / 3 {/tex}
{tex}2{/tex}
{tex} 5 / 3 {/tex}
{tex} 3 / 2 {/tex}
Correct4
Incorrect-1
Which of the following parameters does not characterize the thermodynamic state of matter?
temperature
pressure
{tex} \mathrm {work}{/tex}
volume.
Correct4
Incorrect-1
A Carnot engine takes {tex} 3 \times 10 ^ { 6 } {/tex} cal of heat from a reservoir at {tex} 627 ^ { \circ } \mathrm { C } , {/tex} and gives it to a sink at {tex} 27 ^ { \circ } \mathrm { C } {/tex}. The work done by the engine is
{tex} 4.2 \times 10 ^ { 6 } \mathrm {\ J } {/tex}
{tex} 8.4 \times 10 ^ { 6 } \mathrm {\ J } {/tex}
{tex} 16.8 \times 10 ^ { 6 } \mathrm {\ J } {/tex}
{tex} \mathrm { zero } {/tex}
Correct4
Incorrect-1
One mole of ideal monoatomic gas {tex} ( \gamma = 5 / 3 ) {/tex} is mixed with one mole of diatomic gas {tex} ( \gamma = 7 / 5 ) {/tex}. What is {tex} \gamma {/tex} for the mixture? {tex} \gamma {/tex} denotes the ratio of specific heat at constant pressure, to that at constant volume.
{tex} 3 / 2 {/tex}
{tex} 23 / 15 {/tex}
{tex} 35 / 23 {/tex}
{tex} 4 / 3 {/tex}
Correct4
Incorrect-1
Which of the following statements is correct for any thermodynamic system?
The internal energy changes in all processes.
Internal energy and entropy are state functions.
The change in entropy can never be zero.
The work done in an adiabatic process is always zero.
Correct4
Incorrect-1
Two thermally insulated vessels {tex}1{/tex} and {tex}2{/tex} are filled with air at temperatures {tex} \left( T _ { 1 } , T _ { 2 } \right) , {/tex} volume {tex} \left( V _ { 1 } , V _ { 2 } \right) {/tex} and pressure {tex} \left( P _ { 1 } , P _ { 2 } \right) {/tex} respectively. If the valve joining the two vessels is opened, the temperature inside the vessel at equilibrium will be
{tex} T _ { 1 } + T _ { 2 } {/tex}
{tex} \left( T _ { 1 } + T _ { 2 } \right) / 2 {/tex}
{tex} \frac { T _ { 1 } T _ { 2 } \left( P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } \right) } { P _ { 1 } V _ { 1 } T _ { 2 } + P _ { 2 } V _ { 2 } T _ { 1 } } {/tex}
{tex} \frac { T _ { 1 } T _ { 2 } \left( P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } \right) } { P _ { 1 } V _ { 1 } T _ { 1 } + P _ { 2 } V _ { 2 } T _ { 2 } } {/tex}
Correct4
Incorrect-1
Which of the following is incorrect regarding the first law of thermodynamics?
It introduces the concept of the internal energy
It introduces the concept of entropy
It is not applicable to any cyclic process
It is a restatement of the principle of conservation of energy
Correct4
Incorrect-1
The temperature- entropy diagram of a reversible engine cycle is given in the figure. efficiency is
{tex} 1 / 3 {/tex}
{tex} 2 / 3 {/tex}
{tex} 1 / 2 {/tex}
{tex} 1 / 4 {/tex}
Correct4
Incorrect-1
A system goes from {tex} A {/tex} to {tex} B {/tex} via two processes I and II as shown in
figure. If DU1 and DU2 are the changes in internal energies in the processes I and II respectively, then
{tex} \Delta U _ { 2 } > \Delta U _ { 1 } {/tex}
{tex} \Delta U _ { 2 } < \Delta U _ { 1 } {/tex}
{tex} \Delta U _ { 1 } = \Delta U _ { 2 } {/tex}
relation between {tex} \Delta U _ { 1 } {/tex} and {tex} \Delta U _ { 2 } {/tex} can not be determined
Correct4
Incorrect-1
A gaseous mixture consists of {tex} 16 \mathrm { g } {/tex} of helium and {tex} 16 \mathrm { g } {/tex} of oxygen. The ratio {tex} C _ { P } / C _ { V } {/tex} of the mixture is
{tex} 1.4 {/tex}
{tex} 1.54 {/tex}
{tex} 1.59 {/tex}
{tex} 1.62 {/tex}
Correct4
Incorrect-1
The work of {tex} 146 \mathrm { kJ } {/tex} is performed in order to compress one kilo mole of gas adiabatically and in this process the temperature of the gas increases by {tex} 7 ^ { \circ } \mathrm { C } {/tex}. The gas is {tex} \left( R = 8.3 \mathrm { J } \mathrm { mol } ^ { - 1 } \mathrm { K } ^ { - 1 } \right) {/tex}
monoatomic
diatomic
triatomic
a mixture of monoatomic and diatomic.
Correct4
Incorrect-1
Two rigid boxes containing different ideal gases are placed on a table. Box {tex} A {/tex} contains one mole of nitrogen at temperature {tex} T _ { 0 } , {/tex} while Box {tex} B {/tex} contains one mole of helium at temperature {tex} ( 7 / 3 ) T _ { 0 } . {/tex} The boxes are then put into thermal contact with each other and heat flows between them until the gases reach a common final temperature. (Ignore the heat capacity of boxes. Then, the final temperature of the gases, {tex} T _ { f } {/tex}, in terms of {tex} T _ { 0 } {/tex} is
{tex} T _ { f } = \frac { 5 } { 2 } T _ { 0 } {/tex}
{tex} T _ { f } = \frac { 3 } { 7 } T _ { 0 } {/tex}
{tex} T _ { f } = \frac { 7 } { 3 } T _ { 0 } {/tex}
{tex} T _ { f } = \frac { 3 } { 2 } T _ { 0 } {/tex}
Correct4
Incorrect-1
When a system is taken from state {tex} i {/tex} to state {tex} f {/tex} along the path {tex} iaf, {/tex} it is found that {tex} Q = 50 {/tex} cal and {tex} W = 20 {/tex} cal. Along the path {tex} ibf \ Q = 36 {/tex} cal. W along the path {tex}ibf{/tex} is 
{tex}14 \mathrm {\ cal} {/tex}
{tex} 6 \mathrm {\ cal } {/tex}
{tex} 16 \mathrm {\ cal } {/tex}
{tex}66 \mathrm {\ cal}{/tex}
Correct4
Incorrect-1
A Carnot engine, having an efficiency of {tex} \eta = 1 / 10 {/tex} as heat engine, is used as a refrigerator. If the work done on the system is {tex} 10 \mathrm {\ J } {/tex}, the amount of energy absorbed from the reservoir at lower temperature is
{tex} 100 \mathrm {\ J } {/tex}
{tex} 99 \mathrm {\ J } {/tex}
{tex} 90 \mathrm {\ J } {/tex}
{tex} 1 \mathrm {\ J } {/tex}
Correct4
Incorrect-1
If {tex} C _ { P } {/tex} and {tex} C _ { V } {/tex} denote the specific heats of nitrogen per unit mass at constant pressure and constant volume respectively, then
{tex} C _ { P } - C _ { V } = 28 R {/tex}
{tex} C _ { P } - C _ { V } = R / 28 {/tex}
{tex} C _ { P } - C _ { V } = R / 14 {/tex}
{tex} C _ { P } - C _ { V } = R {/tex}
Correct4
Incorrect-1
An insulated container of gas has two chambers separated by an insulating partition. One of the chambers has volume {tex} V _ { 1 } {/tex} and contains ideal gas at pressure {tex} P _ { 1 } {/tex} and temperature {tex} T _ { 1 } {/tex}. The other chamber has volume {tex} V _ { 2 } {/tex} and contains ideal gas at pressure {tex} P _ { 2 } {/tex} and temperature {tex} T _ { 2 } . {/tex} If the partition is removed without doing any work on the gas, the final equilibrium temperature of the gas in the container will be
{tex} \frac { T _ { 1 } T _ { 2 } \left( P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } \right) } { P _ { 1 } V _ { 1 } T _ { 1 } + P _ { 2 } V _ { 2 } T _ { 2 } } {/tex}
{tex} \frac { T _ { 1 } T _ { 2 } \left( P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } \right) } { P _ { 1 } V _ { 1 } T _ { 2 } + P _ { 2 } V _ { 2 } T _ { 1 } } {/tex}
{tex} \frac { P _ { 1 } V _ { 1 } T _ { 1 } + P _ { 2 } V _ { 2 } T _ { 2 } } { P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } } {/tex}
{tex} \frac { P _ { 1 } V _ { 1 } T _ { 2 } + P _ { 2 } V _ { 2 } T _ { 1 } } { P _ { 1 } V _ { 1 } + P _ { 2 } V _ { 2 } } {/tex}
Correct4
Incorrect-1
For the reactions, {tex} \mathrm { C } + \mathrm { O } _ { 2 } \rightarrow \mathrm { CO } _ { 2 } ; \quad \Delta H = -393 \mathrm { J } {/tex}
{tex} 2 \mathrm { Zn } + \mathrm { O } _ { 2 } \rightarrow 2 \mathrm { ZnO } ; \Delta H = -412 \mathrm { J } {/tex}
carbon can oxidise {tex} \mathrm { Zn } {/tex}
oxidation of carbon is not feasible
oxidation of {tex} \mathrm { Zn } {/tex} is not feasible
{tex} \mathrm { Zn } {/tex} can oxidise carbon.
Correct4
Incorrect-1
If an endothermic reaction is non-spontaneous at freezing point of water and becomes feasible at its boiling point, then
{tex} \Delta H {/tex} is {tex} - \mathrm { ve } , \Delta S {/tex} is {tex} + \mathrm { ve } {/tex}
{tex} \Delta H {/tex} and {tex} \Delta S {/tex} both are {tex} + \mathrm { ve } {/tex}
{tex} \Delta H {/tex} and {tex} \Delta S {/tex} both are {tex} - \mathrm { ve } {/tex}
{tex} \Delta H {/tex} is {tex} + \mathrm { ve } , \Delta S {/tex} is {tex} - \mathrm { ve } {/tex}
