TRANSFORMERS QUIZ

In a transformer the energy is conveyed from primary to secondary

through cooling coil

through air

None of these

by the flux

TRUE ANSWER : ?
YOUR ANSWER : ?

Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is

None of these

great than one

less than one

approximately equal to one

TRUE ANSWER : ?
YOUR ANSWER : ?

A transformer is an efficient device because

Uses electric coupling

Uses capacitive coupling

Uses inductive coupling

A static device

TRUE ANSWER : ?
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In case of 3-phase induction motors, plugging means

starting the motor on load which is more than the rated load

interchanging two supply phases for quick stopping

pulling the motor directly on line without a starter

locking of rotor due to harmonics

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The path of the magnetic flux in transformer should have

low reactance

high reluctance

low resistance

high resistance

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The steel used for transformer core has

High silicon content

High permeability

All of the listed here

Low hysteresis loss

TRUE ANSWER : ?
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When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is

120 V

2,400 V

240 V

12 V

TRUE ANSWER : ?
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The main reason for generation of harmonics in a transformer could be

fluctuating load

mechanical vibrations

poor insulation

saturation of core

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When load on a transformer is increased, the eddy current _____

None of the listed here

Is decreased

Is increased

Remains unchanged

TRUE ANSWER : ?
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The temperature rise of transformer is directly proportional to _______

Leakage reactance

None of the listed here

Apparent power

Reactive power

TRUE ANSWER : ?
YOUR ANSWER : ?

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