ELECTRICAL MACHINES QUIZ

Diverters are used only in

None of these

shunt motors

either of these

series motors

TRUE ANSWER : ?
YOUR ANSWER : ?

Which type motors are preferred for lathes?

Synchronous motor.

Squirrel Cage induction motor.

DC shunt motors.

Either A or B.

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is/are the methods to reduce the armature reaction and its effects?

pole stacking

pole chamfering

All of these

compensating winding

TRUE ANSWER : ?
YOUR ANSWER : ?

Series field consists of--------number of turns and ---------- conductors respectively

large and thick

less and thick

less and thin

large and thin

TRUE ANSWER : ?
YOUR ANSWER : ?

In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs

decrease.

None of these

either of these.

increase.

TRUE ANSWER : ?
YOUR ANSWER : ?

A short-shunt cumulatively-compounded dc generator builds up a voltage of 220 V at no load at rated speed. If it is operated as a differentially compounded generator, other things remaining the same, it would build up

6 V

220 V

more than 220 V

somewhat less than 220 V

TRUE ANSWER : ?
YOUR ANSWER : ?

In which of the following generators negative voltage regulation can occur?

series generators

shunt generator

both B and C

over compound generator

TRUE ANSWER : ?
YOUR ANSWER : ?

In a single phase induction motor driving a fan load, the reason for having a high resistance rotor is to achieve

high efficiency.

reduced size.

quick acceleration.

low starting torque.

TRUE ANSWER : ?
YOUR ANSWER : ?

In a step down transformer which one of the following statements is true?

Number of secondary turns is more than that of primary.

Secondary current is less than primary current.

Secondary power is less than primary power.

Number of secondary turns is less than primary turns.

TRUE ANSWER : ?
YOUR ANSWER : ?

When applied rated voltage per phase is reduce to one half, the starting torque of three phase squirrel cage induction motor becomes

1/4 of the intial value

4 time the initial value

twice the initial value

1/2 of the initial value

TRUE ANSWER : ?
YOUR ANSWER : ?

↑