One mole of an ideal gas at an initial temperature of T K does 6R joule of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 5/3, the final temperature of gas will be
26%
(T + 2.4) K
33%
(T - 2.4) K
30%
(T + 4) K
11%
(T - 4) K
Q.2.
In which process, the PV-indicator diagram is a straight line parallel to volume axis?
25%
Isothermal
42%
Isobaric
12%
Irreversible
21%
Adiabatic
Q.3.
If the temperature of the source is increased, the efficiency of a Carnot engine?
45%
Increases
15%
Decreases
20%
Remain constant
20%
First increases and then remain constant
Q.4.
An ideal gas A and a real gas B have their volumes increased from V to 2V under isothermal conditions . The increase in internal energy
17%
Will be the same in both A and B
33%
Will be zero in both the gases
39%
Of B will be more than that of A
11%
Of B will be more than that of A
Q.5.
In a Carnot cycle, order of process is
38%
isothermal expansion, adiabatic expansion and adiabatic compression
25%
isothermal expansion, adiabatic compression and adiabatic expansion
19%
adiabatic expansion, isothermal expansion and adiabatic compression
19%
none of the above
Q.6.
A diatomic ideal gas is compressed adiabatically to 1/32 of its initial volume. If the initial temperature of the gas is $T_i$ ( in kelvin) and the final temperature is $pT_i$. The value of p is
7%
1
43%
2
43%
3
7%
4
Q.7.
In a given process on an ideal gas, dW=0 and dQ
27%
$\Delta T > 0$
33%
$\Delta T < 0$
33%
$\Delta T =0$
7%
Insufficient information
Q.8.
During adiabatic compression of a gas, its temperature
7%
Falls
79%
Remains constant
14%
Rises
0%
Becomes zero
Q.9.
A given mass of a gas is compressed isothermally until its pressure is doubled. It is then allowed to expand adiabatically until its original volume is restored and its pressure is then found to be 0.75 of its initial pressure. The ratio of the specific heats of the gas is approximately
27%
1.20
0%
1.41
36%
1.67
36%
1.83
Q.10.
“Heat cannot by itself flow from a body at a lower temperature to a body at higher temperature” is a statement of the consequence of
33%
the second law of thermodynamics
25%
conservation of momentum
42%
conservation of mass
0%
the first law of thermodynamics.
Q.11.
In the following questions, a statement of assertion is followed by a statement of reason. You are required to choose the correct one out of the given four responses and mark it as
(a) If both assertion and reason are true and reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not correct explanation of the assertion.
(c) If assertion is true, but reason is false.
(d) If both assertion and reason are false.
(e) If reason is true but assertion is false
Assertion: In an isolated system, the entropy increases
Reason : The processes in an isolated system are adiabatic
50%
(a)
12%
(b)
25%
(c)
12%
(d)
0%
(e)
Q.12.
In the following questions, a statement of assertion is followed by a statement of reason. You are required to choose the correct one out of the given four responses and mark it as
(a) If both assertion and reason are true and reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not correct explanation of the assertion.
(c) If assertion is true, but reason is false.
(d) If both assertion and reason are false.
(e) If reason is true but assertion is false
Assertion: The Carnot cycle is useful in understanding the performance of heat engines.
Reason: The Carnot cycle provides a way of determining the maximum possible efficiency achievable with reservoirs of given temperatures
33%
(a)
17%
(b)
33%
(c)
0%
(d)
17%
(e)
Q.13.
In the following questions, a statement of assertion is followed by a statement of reason. You are required to choose the correct one out of the given four responses and mark it as
(a) If both assertion and reason are true and reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not correct explanation of the assertion.
(c) If assertion is true, but reason is false.
(d) If both assertion and reason are false.
(e) If reason is true but assertion is false
Assertion: Air quickly leaking out of a balloon becomes cooler.
Reason: The leaking air undergoes adiabatic expansion.
0%
(a)
17%
(b)
67%
(c)
0%
(d)
17%
(e)
Q.14.
In the following questions, a statement of assertion is followed by a statement of reason. You are required to choose the correct one out of the given four responses and mark it as|
(a) If both assertion and reason are true and reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not correct explanation of the assertion.
(c) If assertion is true, but reason is false.
(d) If both assertion and reason are false.
(e) If reason is true but assertion is false
Assertion: The temperature of the surface of the sun is approx. 6000K. if we make a big lens and focus the sun rays, we can produce a temperature of 8000K
Reason: The higher temperature can be produced accordingly to the second law of thermodynamics
50%
(a)
17%
(b)
0%
(c)
33%
(d)
0%
(e)
Q.15.
An ideal gas having initial pressure P, volume V and temperature T is allowed to expand adiabatically until its volume becomes 5.66V while its temperature falls to T/How many degrees of freedom do the gas molecules have?
18%
5
36%
6
36%
7
9%
8
Q.16.
Obtain the workdone by a gas dring the expansion as a function of the initial pressure P and Volume V
33%
3/2 PV
56%
5/4 PV
0%
1/2 PV
11%
3/4 PV
Q.17.
A monotonic gas is taken through ABCDA cycle.
A->B Constant Pressure process
B->C Constant volume process
C->D Constant Pressure process
D->A Constant volume process
The PV coordinates of point A are (P,V)
The PV coordinates of point B are (P,3V)
The PV coordinates of point C are (3P,3V)
The PV coordinates of point D are (3P,V)
then which of the following is not true
0%
total work done in the cycle is -4V
70%
Change in Internal energy =0
20%
total work done in the cycle is 4V
10%
Work done in Process CD=-6PV
Q.18.
The first law of thermodynamics dU=dQ-dW,indicates that when a system goes from its initial state to a final state
40%
dU is same for every path
10%
dQ is same for every path
20%
dQ+dW is same for every path
30%
dQ-2dW is same for every path
Q.19.
A gas is contained in a vertical, friction less piston cylinder device. The piston has a mass of 20 kg with a cross-sectional area of 20 cm2 and is pulled with a force of 100N. If the atmospheric pressure is 100 kPa, determine the pressure inside.
20%
110 kPa
10%
100kPa
40%
150kPa
30%
200 Kpa
Q.20.
For an adiabatic process
33%
$\Delta S=0$
44%
$\Delta U=0$
0%
Q =0
22%
W=0
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