Mechanical Engineering - Thermodynamics

31.
The general gas energy equation is (where Q1 - 2 = Heat supplied, dU = Change in internal energy, and W1 - 2 = Work done in heat units)
Q1 - 2 = dU + W1 - 2
Q1 - 2 = dU - W1 - 2
Q1 - 2 = dU/W1 - 2
Q1 - 2 = dU x W1 - 2
Answer: Option
Explanation:
No answer description is available. Let's discuss.

32.
The compression ratio for Diesel engines is
3 to 6
5 to 8
15 to 20
20 to 30
Answer: Option
Explanation:
No answer description is available. Let's discuss.

33.
In an isothermal process,
there is no change in temperature
there is no change in enthalpy
there is no change in internal energy
all of these
Answer: Option
Explanation:
No answer description is available. Let's discuss.

34.
Which of the following is the correct statement of the second law of thermodynamics?
It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work.
It is impossible to transfer heat from a body at a lower temperature to a higher temperature, without the aid of an external source.
There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy.
all of the above
Answer: Option
Explanation:
No answer description is available. Let's discuss.

35.
The heating and expanding of a gas is called thermodynamic system.
Yes
No
Answer: Option
Explanation:
No answer description is available. Let's discuss.