MAGNETIC CIRCUIT QUIZ

The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is ___________Vs

500

70

20

50

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YOUR ANSWER : ?

Point out the wrong statement. Magnetic leakage is undesirable in electric machines because it

Produces fringing

Increases their cost of manufacture

Lowers their power efficiency

Leads to their increased weight

TRUE ANSWER : ?
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Permeability in a magnetic circuit corresponds to_________ in an electric circuit.

Conductance

Conductivity

Resistance

Resistivity

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Laminated cores, in electrical machines, are used to reduce

Eddy current loss

Hysteresis loss

Copper loss

All of the listed here

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Conductance is analogous to

Flux

Permeance

Reluctance

Inductance

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The unit of magnetic flux is

Ampere/metre

Ampere-turn/weber

Weber

Henry

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A material for good magnetic memory should have

Low hysteresis loss

High permeability

Low retentivity

High retentivity

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An air gap is usually inserted in magnetic circuits to

None of the listed here

Increase m.m.f.

Increase the flux

Prevent saturation

TRUE ANSWER : ?
YOUR ANSWER : ?

The unit of reluctance is

Henry

1/Henry

Meter/Henry

Henry/meter

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Hysteresis loss least depends on

Ambient temperature

Steinmetz’s coefficient of material

Frequency

Volume of material

TRUE ANSWER : ?
YOUR ANSWER : ?

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