Electrical Engineering Mcqs Practice Test

Question 1

If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________?

Accepted Answer

B. Vs/Vp = Ns/Np

Question 2

A metal rod of 25 cm length is moving at a speed of 0.5/sec in direction perpendicular to 0.25T magnetic field. Emf produced in the rod is_____________?

Accepted Answer

D. 0.03125 volt

Question 3

The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core_______________?

Accepted Answer

C. Improves the flux linkage between the turns of the coil

Question 4

An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4×10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum speed of the aeroplane is____________?

Accepted Answer

B. 384msec-1

Question 5

Non inductive resistances are used in decreasing______________?

Accepted Answer

B. Self inductance

Question 6

Which one of the following devices does not function like an electric motor ?

Accepted Answer

D. Transformer

Question 7

For long distance transmission the transformer used is_____________?

Accepted Answer

C. Step up

Question 8

Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the magnetic field is varied is known as magnetic_____________?

Accepted Answer

D. Hysteresis

Question 9

When the motor is at its maximum speed then back emf will be______________?

Accepted Answer

A. Maximum

Question 10

Transformer works on the principle of________________?

Accepted Answer

C. Mutual induction

Question 11

An electric current induced within the body of a conductor when that conductor either moves through a non uniform magnetic field or in a region where there is a change in magnetic flux is called_____________?

Accepted Answer

B. Eddy current

Question 12

The out put voltage of a transformer is 3 times the input voltage then turns ratio will be________________?

Accepted Answer

B. 3

Question 13

Long distance transmission is easy for________________?

Accepted Answer

B. A.C voltage

Question 14

Magnetic compass needle will be deflecting if it is kept near________________?

Accepted Answer

D. Accelerating charge

Question 15

A.C can not be used for_______________?

Accepted Answer

C. Magnetizing iron

Question 16

A small coil lies inside a large coil. The two coils are horizontal concentric and carry currents in opposite directions. The large coil will experience______________?

Accepted Answer

D. No resultant force

Question 17

The emf induced in a conductor of unit length moving with unit velocity at right angles to a magnetic field is equal to_____________?

Accepted Answer

A. Magnetic flux density

Question 18

The emf induced in a coil by a changing magnetic flux may have unit as______________?

Accepted Answer

D. kgm2s-1A-1

Question 19

Power loss in actual transformer is due to_________________?

Accepted Answer

B. Eddy currents and magnetic hysterias

Question 20

A.C and D.C have the same______________?

Accepted Answer

D. heating effect through a resistance