250+ TOP MCQs on USM – Factors Affecting MRR and Answers

Advanced Machining Processes Multiple Choice Questions on “USM – Factors Affecting MRR”.

1. What happens to MRR with increase in tool amplitude?
a) Increases
b) Decreases
c) Remains same
d) None of the mentioned
Answer: a
Clarification: As amplitude of the tool increases, rate of material removal increases.

2. The vibration amplitude determines, which parameter of the abrasive particles?
a) Force
b) Torque
c) Velocity
d) Pressure
Answer: c
Clarification: Amplitude determines the velocity of abrasive particles between tool and work piece.

3. If splashing occurs, it will result in an increase of material removal rate in USM.
a) True
b) False
Answer: b
Clarification: Splashing occurs if amplitude is very high which in turn decreases the material removal rate.

4. Amplitude of the oscillation ranges between which of the following values?
a) 0.01 – 0.04 mm
b) 0.04 – 0.08 mm
c) 0.08 – 0.10 mm
d) 0.10 – 0.20 mm
Answer: b
Clarification: Optimum value of the amplitude of the tool will vary between 0.04-0.08 mm.

5. As the vibration frequency increases, what happens to material removal rate?
a) Decreases
b) Increases
c) Increase and then decrease
d) Decrease and then increase
Answer: c
Clarification: Up to a certain limit of vibration frequency, MRR increases and after that it decreases.

6. Which of the following can be used as an abrasive carrying medium?
a) Water
b) Benzene
c) Glycerol
d) All of the mentioned
Answer: d
Clarification: Any of the above liquids can be used as abrasive carrying medium.

7. If there is an increase in viscosity of slurry, what happens to MRR?
a) Increases
b) Decreases
c) Remains same
d) None of the mentioned
Answer: b
Clarification: As viscosity is increased, material removal rate is decreased.

8. How much percent of the abrasives are recommended in general for abrasive medium?
a) 10 – 15 %
b) 15 – 20 %
c) 25 – 30 %
d) 30 – 35 %
Answer: d
Clarification: In practice, volumetric concentration of abrasives used range between 30 – 35 %.

9. Machining rate can be affected by the ratio of hardness of tool to that of hardness of work piece.
a) True
b) False
Answer: a
Clarification: In USM, Machining rate increases as the mentioned ratio decreases and vice-versa.

10. As the tool area increases, what happens to MRR?
a) Decreases
b) Increases
c) Remains same
d) None of the mentioned
Answer: a
Clarification: An increase in tool area distributes grains over the work piece, which reduces the machining rate.

11. When the static pressure of the feed is increases, what happens to MRR?
a) Increases
b) Decreases
c) Increase up to a limiting condition
d) Decrease up to a limiting condition
Answer: c
Clarification: As static feed pressure increases, MRR increases up to a limiting condition and then no further increase takes place.