GATE ME 1. Thermodynamics Chapter Thermodynamics Test

Question 1
2 / -0.33

The first law of thermodynamics takes the form W = -ΔH when applied to

A
A closed system undergoing a reversible adiabatic process

B
An open system undergoing an adiabatic process with negligible changes in kinetic and potential energies

C
A closed system undergoing a reversible constant volume process

D
A closed constant pressure process

Question 2
2 / -0.33

A system containing air undergoes a change of state from (P₁, V₁) to (P₂, V₂) whose values are (0.5 MPa, 0.287 m³/kg) and (0.1 MPa, 1.435 m³/kg) respectively. The process undergone by the system is

A
Isochoric

B
isobaric

C
Isothermal

D
Isentropic

Question 3
2 / -0.33

1800 kJ of heat is transferred from condensing steam at 600 K to vaporizing water at 450 K. The atmospheric temperature is 300 K. The net decrease of availability for overall process of heat transfer in kJ is

A
1200

B
900

C
600

D
300

Question 4
2 / -0.33

For the given parameters a & b of the given equation.
\(\left( p+~\frac{a}{{{\nu }^{2}}} \right)\left( \nu -b \right)=RT\)
Which of the following is correct?

A
Units of a and b are \(\frac{{{m}^{5}}}{kg{{\sec }^{2}}}\) and \(\frac{{{m}^{3}}}{kg}\) respectively

B
b accounts for intermolecular forces

C
a accounts for volume occupied by gas molecules

D
None of the above

Question 5
2 / -0.33

An ideal gas at 100 kPa pressure and 300 K temperature with a volume of 0.5 m³ undergoes isothermal expansion to a pressure of 50 kPa. The standard properties of an ideal gas can be assumed when needed.

A
The work done by the gas during expansion is + 34.65 kJ

B
The heat added to the gas during expansion is + 34.65 kJ

C
The work done by the gas during expansion is - 34.65 kJ

D
The heat added to the gas during expansion is - 34.65 kJ

Question 6
2 / -0.33

A car tyre of volume 0.05 m³ is inflated to 300 kPa at 300 K. After the car driven for 10 hours, the pressure in tyre increases to 330 kPa. Assume air as ideal gas and C_v = 21 J/mol.k. The change in internal energy for air in tyre in J/mol is

A
627-633

B
6274-6331

C
6277-6336

D
6279-6332

Question 7
2 / -0.33

Atmospheric air (R = 287 J/kg; γ = 1.4) at 1 bar and 25°C is compressed adiabatically to 2 bar and 105°C. Which of the following statement is correct?

A
Process is possible but irreversible

B
Process is possible but reversible

C
Process is impossible

D
Process is possible and it is isentropic

Question 8
2 / -0.33

Which of the following equations are in the correct form?
“a” → Helmboltz function
“g” → Gibbs function
P. du = Tds + pdV
Q. dh = Tds + VdT
R. da = -sdT – pdV
S. dg = -sdT + Vdp

A
P

B
Q

C
R

D
S

Question 9
2 / -0.33

Which of the following is correct for the mixture of ideal gases?

A
\({R_e} = \frac{{\sum \left( {R} \right)}}{{\sum m}}\)

B
\({C_{ve}} = \frac{{\sum \left( {m{C_v}} \right)}}{{\sum 2m}}\)

C
\({C_{pe}} = \frac{{\sum \left( {m{C_p}} \right)}}{{\sum m}}\)

D
All the above

Question 10
2 / -0.33

One kg of air (that can be considered a calorically perfect gas with characteristic gas constant R = 287 J/kg K and specific heat ratio γ = 1.4) undergoes a constant volume process from an initial static pressure of 1 bar to a final static pressure of 4 bar. The increase in entropy (in J/kg-K) of air is ________.

A
990-1000

B
9904-10001

C
9907-10006

D
9909-10002

Question 11
2 / -0.33

1 kg of air is compressed polytropically (PV^1.123 = 3) from 1 bar pressure and temperature of 300 K to a pressure of 6.8 bar and temperature of 370 K. Determine the irreversibility (in kJ) if the atmosphere temperature is 293 K.
Assume R = 0.287 kJ/kg.K. C_p = 1.004 kJ/kg K and C_v = 0.716 kJ/kg.K

A
13.4-14.1

B
13.44-14.11

C
13.47-14.16

D
13.49-14.12

Question 12
2 / -0.33

A tank contains m kg of liquid water at an initial temperature T₀°C. A coil removes heat at the rate of Q = K₁T from the tank. A paddle wheel, by constantly stirring, maintains uniform temperature in the tank. The rate of work input through paddle wheel is W = K₂T. Temperature T is in °C and K₁ and K₂ are constants. Then which of the following statements are true.

A
\(T = {T_0}{e^{\left( {\frac{{{K_2} - {K_1}}}{{m{c_v}}}} \right)t}}\)

B
\(T = \;{T_0}{e^{\left( {\frac{{{K_1} - {K_2}}}{{m{c_v}}}} \right)t}}\)

C
If |k2|>|k1|, temperature will increase exponentially

D
If |k2|>|k1|, temperature will decrease exponentially

Question 13
2 / -0.33

Steady heat transfer takes place through plane wall in the outward direction at the rate of 1500 W. The inner surface temperature of wall is 27°C. The entropy generation is 0.25 W/K. The outer surface temperature of wall is _______

A
2.7°c

B
5.1°c

C
7.2°c

D
12.7°c

Question 14
2 / -0.33

Carbon Tetrachloride boils at 76°C and 101 kPa. The latent heat of the vaporisation of carbon tetrachloride is 195 kJ/Kg and for this characteristic gas constant is 0.055 kJ/kgK. Then which of the following statements are true?

A
The boiling point of carbon-tetrachloride at 202 kPa is 101.55 °C

B
The boiling point of carbon-tetrachloride at 303 kPa is 118.32 °C

C
The boiling point of carbon-tetrachloride at 202 kPa is 118.32 °C

D
The boiling point of carbon-tetrachloride at 303 kPa is 101.55 °C

Question 15
2 / -0.33

A fluid is confined in a cylinder by a spring loaded frictionless piston so that the pressure in the fluid is a linear function of volume. The internal energy of fluid is given by following equation, v = 34 + 3.15 pV
Where U is in kJ, p in kPa and V in m³
If the fluid changes from initial state of 170 kPa, 0.03 m³ to final state of 400 kPa, 0.06 m³. Find the amount of work done & heat transfer

A
W = -8.55 kJ, Q = 50.95 kJ

B
W = -8.55 kJ, Q = 68.05 kJ

C
W = 8.55 kJ, Q = 50.95 kJ

D
W = 8.55 kJ, Q = 68.05 kJ

Question 16
2 / -0.33

A mixture of freon and air is supplied for cleaning a chamber. The mixture contains 70 % volume of air and 30 % volume of Freon. Specific heat ratios for Freon and air are 1.1 & 1.4 respectively. Molecular mass of Freon is 200 gm/mol and that air is 30 gm/mol. Temperature of gas is 300 K. If universal gas constant is 8.314 J/mol k then specific heat ratio of mixture is

A
1.16

B
1.21

C
1.25

D
1.31

Question 17
2 / -0.33

A pressure cooker of capacity 4L has an operating pressure of 160 KPa. The cooker is initially at operating pressure and contains two-phase liquid vapor mixture of quality 0.006. The heater is rated 1kW and at the end of cooking, the amount of steam escaped is found to be 0.2 kg. Then
Saturated:
P (MPa)
T_sat(°C)
V_f (m³/kg)
V_g
(m³/kg)
u_f
(kJ/kg)
u_g (kJ/kg)
h_f (kJ/kg)
h_g
(kJ/kg)
0.16
113.3
0.00105440
1.0914
475.21
2521.4
475.38
2696

A
The quality of the steam at the end of the cooking is 0.01

B
The cooking temperature of the cooker is 100°C

C
The heater is on for 7.4 min

D
The initial mass of the water vapor mixture is 0.526 kg

Question 18
2 / -0.33

A vessel has two compartments. First compartment contains 2 kg of dry saturated steam at 7 bar [v_g@7bar = 0.27 m³/kg] and second compartment contains 1 kg of steam of dryness fraction of 0.8 at 3.5 bar [v_{g@ 3.5 bar} = 0.55 m³/kg]. After the partition is removed, the pressure of the mixture is found to be 5 bar [v_{g@5 bar}= 0.37 m³/kg]. Neglecting the volume of water, what will be the specific volume of mixture?

A
0.281 m³/kg

B
0.326 m³/kg

C
0.462 m³/kg

D
0.521 m³/kg

Submit Test

Thermodynamics ...

Question 1

A closed system undergoing a reversible adiabatic process

An open system undergoing an adiabatic process with negligible changes in kinetic and potential energies

A closed system undergoing a reversible constant volume process

A closed constant pressure process

Question 2

Isochoric

isobaric

Isothermal

Isentropic

Question 3

1200

900

600

300

Question 4

Units of a and b are \(\frac{{{m}^{5}}}{kg{{\sec }^{2}}}\) and \(\frac{{{m}^{3}}}{kg}\) respectively

b accounts for intermolecular forces

a accounts for volume occupied by gas molecules

None of the above

Question 5

The work done by the gas during expansion is + 34.65 kJ

The heat added to the gas during expansion is + 34.65 kJ

The work done by the gas during expansion is - 34.65 kJ

The heat added to the gas during expansion is - 34.65 kJ

Question 6

627-633

6274-6331

6277-6336

6279-6332

Question 7

Process is possible but irreversible

Process is possible but reversible

Process is impossible

Process is possible and it is isentropic

Question 8

P

Q

R

S

Question 9

\({R_e} = \frac{{\sum \left( {R} \right)}}{{\sum m}}\)

\({C_{ve}} = \frac{{\sum \left( {m{C_v}} \right)}}{{\sum 2m}}\)

\({C_{pe}} = \frac{{\sum \left( {m{C_p}} \right)}}{{\sum m}}\)

All the above

Question 10

990-1000

9904-10001

9907-10006

9909-10002

Question 11

13.4-14.1

13.44-14.11

13.47-14.16

13.49-14.12

Question 12

\(T = {T_0}{e^{\left( {\frac{{{K_2} - {K_1}}}{{m{c_v}}}} \right)t}}\)

\(T = \;{T_0}{e^{\left( {\frac{{{K_1} - {K_2}}}{{m{c_v}}}} \right)t}}\)

If |k2|>|k1|, temperature will increase exponentially

If |k2|>|k1|, temperature will decrease exponentially

Question 13

2.7°c

5.1°c

7.2°c

12.7°c

Question 14

The boiling point of carbon-tetrachloride at 202 kPa is 101.55 °C

The boiling point of carbon-tetrachloride at 303 kPa is 118.32 °C

The boiling point of carbon-tetrachloride at 202 kPa is 118.32 °C

The boiling point of carbon-tetrachloride at 303 kPa is 101.55 °C

Question 15

W = -8.55 kJ, Q = 50.95 kJ

W = -8.55 kJ, Q = 68.05 kJ

W = 8.55 kJ, Q = 50.95 kJ

W = 8.55 kJ, Q = 68.05 kJ

Question 16

1.16

1.21

1.25

0.281 m³/kg

0.326 m³/kg

0.462 m³/kg

0.521 m³/kg