Machine Design MCQs

Question 1

In induction motors, power supply is connected to

Accepted Answer

Stator only

Answer

Rotor only

Answer

Both rotor and stator

Answer

Any one of (a) or (b) above

Question 2

The speed of synchronous motor having 8 poles and operating at 50 c/s power supply will be

Accepted Answer

750 r.p.m.

Answer

1000 r.p.m.

Answer

600 r.p.m.

Answer

800 r.p.m.

Question 3

Which is false statement about induction motors

Accepted Answer

Its starting torque is more than d.c. shunt motor

Answer

Its speed decreases with increase in load

Answer

Its direction of rotation can be changed by interchanging two phases

Answer

Its speed can't be controlled without sacrificing efficiency

Question 4

The phenomenon of hunting is observed in

Accepted Answer

Synchronous motor

Answer

Induction motors

Answer

D.C. shunt motors

Answer

D.C. series motor

Question 5

Helical springs are not subjected to

Accepted Answer

Hoop stress

Answer

Force 329

Answer

Deflection

Answer

Torsional shear stress

Question 6

The welding units operate at following power factor

Accepted Answer

0.3

Answer

0.6

Answer

0.8

Answer

0.9

Question 7

For traction applications, following type of motor is used

Accepted Answer

D.C. series motor

Answer

Induction motor

Answer

Synchronous motor

Answer

D.C. shunt motor

Question 8

The most commonly used motor in applications like elevator, machine tools is

Accepted Answer

Induction (squirrel cage) motor

Answer

D.C. series motor

Answer

D.C. shunt motor

Answer

Synchronous motor

Question 9

In a simply supported beam, where the shear force is zero, the bending moment will be

Accepted Answer

Maximum

Answer

Zero

Answer

Minimum

Answer

Could be anything