MAGNETIC CIRCUIT QUIZ

Ferrites have high hysteresis

None of the listed here

Ferrites have high resistance

Ferrites have high resistance

Ferrites have low permeability

TRUE ANSWER : ?
YOUR ANSWER : ?

Silicon steel is used in electrical machines because it has

Low retentivity

High coercivity

Low hysteresis loss

Low coercivity

TRUE ANSWER : ?
YOUR ANSWER : ?

The unit of retentivity is

Ampere turns

Ampere turn/meter

Weber

Weber/sq. m

TRUE ANSWER : ?
YOUR ANSWER : ?

Conductivity is analogous to

Resistivity

Retentivity

Permeability

Inductance

TRUE ANSWER : ?
YOUR ANSWER : ?

Laminated cores, in electrical machines, are used to reduce

All of the listed here

Eddy current loss

Copper loss

Hysteresis loss

TRUE ANSWER : ?
YOUR ANSWER : ?

When both the inductance and resistance of a coil are doubled the value of

Time constant remains unchanged

Time constant is halved

Final steady current is doubled

Initial rate of rise of current is doubled

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Produces fringing

Lowers their power efficiency

Increases their cost of manufacture

Leads to their increased weight

TRUE ANSWER : ?
YOUR ANSWER : ?

Reciprocal of reluctance is

Susceptibility

Permeability

Permeance

Reluctivity

TRUE ANSWER : ?
YOUR ANSWER : ?

The unit of magnetic flux is

Ampere-turn/weber

Weber

Henry

Ampere/metre

TRUE ANSWER : ?
YOUR ANSWER : ?

The relative permeability of a ferromagnetic material is

More than 100 Ωr 1000

More than 10

Less than one

More than one

TRUE ANSWER : ?
YOUR ANSWER : ?

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