# 250+ TOP MCQs on Internal Energy and Energy Conversion Concept and Answers

Basic Chemical Engineering Multiple Choice Questions & Answers (MCQs) on “Internal Energy and Energy Conversion Concept”.

1. What is the change in internal energy for a process which has final and initial states are exactly similar?
a) Positive
b) Negative
c) Zero
d) Cannot say

Clarification: Since internal energy is a state function, change in internal energy for the process will be zero.

2. What is the change in internal energy of 2 mole of air (Cv = 2.1 X 104 J/moleoC), if its temperature changes from 10oC to 20oC?
a) 420 kJ
b) 540 kJ
c) 840 kJ
d) 1050 kJ

Clarification: Change in internal energy = 2*(2.1 X 104)*(20 – 10) = 420 kJ.

3. What is the change in internal energy of 1 mole of air ((Cv = 2.1 X 104 J/moleoC), if its temperature changes from 10oC to 5oC?
a) 84 kJ
b) 105 kJ
c) – 84 kJ
d) – 105 kJ

Clarification: Change in internal energy = 1*(2.1 X 104)*(5 – 10) = – 105 kJ.

4. Ratio of change in internal energy of a substance from 4oC to T and from T to 10oC is 2, what is T?
a) 5oC
b) 6oC
c) 7oC
d) 8oC

Clarification: 2 = (T – 4)/(10 – T), => T = 8oC.

5. Ratio of change in internal energy of a substance from 15oC to T and from T to 10oC is – 2, what is T?
a) 5oC
b) 15oC
c) 20oC
d) 30oC

Clarification: – 2 = (T – 15)/(10 – T), => T = 5oC.

6. Total energy of the universe is always ______
a) Increasing
b) Decreasing
c) Constant
d) Cannot say

Clarification: According to the law of conservation of energy, the total energy of the universe is always constant.

7. A stone has initial potential and kinetic energy as 10 J and 5 J respectively if the final potential energy of the stone is 15 J what is its final kinetic energy?
a) 0
b) 5 J
c) 10 J
d) 15 J

Clarification: Law of conservation of energy, 10 + 5 = 15 + KE, => KE = 0.

8. A stone has initial potential and kinetic energy as 5 J and 20 J respectively if the final kinetic energy of the stone is 15 J what is its final potential energy?
a) 0
b) 10 J
c) 15 J
d) 25 J

Clarification: 5 + 20 = 15 + PE, => PE = 10 J.

9. A stone has initial potential, kinetic and internal energy 4 J, 15 J and 20 J respectively, if the final kinetic energy and potential energy of the stone is 5 J and 10 J respectively, what is the final internal energy?
a) 15 J
b) 20 J
c) 24 J
d) 32 J