Those magnetic materials are best suited for making armature and transformer cores which have ________permeability and _________hysteresis loss.

Those materials are well suited for making permanent magnets which have ________ retentivity and ________ coercivity.

A

Low, high

B

High, high

C

High, low

D

Low, low

Transformer cores are normally made from

A

soft ferrites

B

high purity iron

C

grain oriented Fe-Si alloy

D

AlNiCo alloy

The sand used for making cores is

A

Green sand

B

Dry sand

C

Loam sand

D

Oil sand

‘Those who live in glass houses should not throw stones.’ Which of the following suited best to match with mentioned sentence/s?

A

you do me a favor and I will reciprocate.

B

It is wise not to disturb things at times lest you invite trouble

C

Think of your own mistakes before blaming others.

D

Stay is vulnerable condition should not attack others.

The materials which fracture even at small strains are termed as brittle, while those materials which exhibit an appreciable deformation before failure are termed as

A

Rigid

B

Tough

C

Ductile

D

Plastic

Thermoplastic materials are those materials which

A

Do not become hard with the application of heat and pressure and no chemical change occurs

B

Are flexible and can withstand considerable wear under suitable conditions

C

Are formed into shape under heat and pressure and results in a permanently hard product

D

Are used as a friction lining for clutches and brakes

The path of a magnetic flux in a transformer should have

A

high resistance

B

high reluctance

C

low resistance

D

low reluctance

The path of the magnetic flux in transformer should have

A

high reluctance

B

low reactance

C

high resistance

D

low resistance

The changes in volume of transformer cooling oil due to variation of atmospheric tem-perature during day and night is taken care of by which part of transformer

A

Conservator

B

Breather

C

Bushings

D

Buchholz relay

Which of the following is the main advantage of an auto-transformer over a two-winding transformer?

A

Eddy losses are totally eliminated

B

Copper losses are negligible

C

Saving in winding material

D

Hysteresis losses are reduced

Those magnetic materials are best suited for making armature and transformer cores which have permeability and _hysteresis loss.

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