1. In Ultrasonic Machining, Magnetostrictor is energized at ultrasonic frequency.
a) True
b) False
Explanation: To oscillate, magnetostrictor must be energized to the ultrasonic frequency in USM.
2. Of the following scientists, who discovered magnetostrictor effect?
a) Balamuth
b) Steve O Flawer
c) Joule
d) Turing
Explanation: This effect was discovered by Joule in 1874 at Manchester.
3. In Ultrasonic Machining, magnetostrictor converts magnetic energy into which type of energy?
a) Mechanical energy
b) Electrical energy
c) Thermal energy
d) None of the mentioned
Explanation: Oscillation of magnetostrictor takes place by converting magnetic energy to mechanical energy.
4. What is the value of the amplitude obtained without mechanical amplifier?
a) 0.0001 – 0.001 µm
b) 0.001 – 0.1 µm
c) 1 – 10 µm
d) 10 – 100 µm
Explanation: Relatively very small amplitudes are obtained without amplifier.
5. What is the value of the amplitude obtained when we use mechanical amplifier?
a) 1 – 10 µm
b) 10 – 40 µm
c) 40 – 50 µm
d) 50 – 100 µm
Explanation: Relatively larger amplitudes are obtained when amplifier is used.
6. In USM, tool tips must have low resistance and fatigue strength.
a) True
b) False
Explanation: In USM, tool tips should must have high wear resistance and fatigue strength.
7. At what rate slurry is pumped through nozzle in USM?
a) 10 L/min
b) 25 L/min
c) 50 L/min
d) 75 L/min
Explanation: Slurry is pumped through nozzle at the rate of 25 L/min, L- litres.
8. By which of the following means, material is removed in USM?
a) Mechanical abrasion
b) Microchipping
c) Cavitation
d) All of the mentioned
Explanation: In Ultrasonic Machining, material is removed by any of the above means.
9. What is the percentage of contribution of cavitation to the total material removed?
a) <5%
b) 5 – 10 %
c) 10 – 20 %
d) 20 – 50 %
Explanation: Cavitation contributes to only less than 5 % of total material removed.
10. In the following mechanisms, which one is dominant in material removal?
a) Hammering
b) Cavitation
c) Microchipping
d) None of the mentioned
Explanation: Hammering is dominant mechanism in material removal of USM.