FREE EIT Thermodynamics and Strength of Materials Questions and Answers

Question 1

A cantilever beam is loaded with a force of 10 KN and has a cross-section as shown. The maximum tensile stress in MPa in the beam most nearly is:

Accepted Answer

441

Answer

4.16

Answer

588

Answer

735

Question 2

The maximum tensile principal stress in MPa for the two-dimensional stress state given is:

Accepted Answer

30

Answer

20

Answer

40

Answer

60

Question 3

In all adiabatic processes, there is:

Accepted Answer

no heat flow

Answer

no change in temperature

Answer

no change in enthalpy

Answer

All of the above

Question 4

A Carnot refrigerator operates between 10°𝐶𝐶 and 25°𝐶𝐶. The coefficient of performance is:

Accepted Answer

18.9

Answer

0.0500

Answer

0.667

Answer

19.9

Question 5

Air in a closed-rigid vessel at 2 bars and 25°𝐶𝐶 is heated until its temperature is 100°𝐶𝐶. The final pressure in bars is:

Accepted Answer

2.50

Answer

4.40

Answer

8.00

Answer

256.0

Question 6

Air is adiabatically compressed in a steady flow system from 1 bar to 5 bars. The air enters at 298 K and the compressor efficiency is 70 %. The work per unit mass of air required for the compression (in kJ/kg) is:

Accepted Answer

249

Answer

122

Answer

174

Answer

1703

Question 7

A 1-meter diameter steel cylindrical tank is used to store propane at high pressure. If the allowable stress of steel is 100 MPa and the propane is stored at a pressure of 1000 kPa, the minimum thickness in mm of the tank is:

Accepted Answer

5.0

Answer

7.5

Answer

10

Answer

20

Question 8

At what point in a Carnot cycle does heat rejection occur?

Accepted Answer

Adiabatic expansion

Answer

Isothermal compression

Answer

Adiabatic compression

Answer

Isothermal expansion

Question 9

What is the purpose of a condenser in a Rankine cycle?

Accepted Answer

To convert the working fluid from vapor to liquid

Answer

To increase the temperature of the working fluid

Answer

To reduce the pressure of the working fluid

Answer

To remove moisture from the working fluid

Question 10

Which property of a substance remains constant during an isentropic process?

Accepted Answer

Entropy

Answer

Temperature

Answer

Pressure

Answer

Volume