Electrical Engineering Mcqs Practice Test

Question 1

Which of the following is the loss within the mercury arc rectifier chamber ?

Accepted Answer

D. All of the above

Question 2

Which of the following rectifiers are primarily used for charging of low voltage batteries from AC supply ?

Accepted Answer

D. Electrolytic rectifiers

Question 3

The efficiency of an electrolytic rectifier is nearly____________?

Accepted Answer

C. 60%

Question 4

The ignited or auxiliary anode in mercury arc rectifier is made of____________?

Accepted Answer

B. boron carbide

Question 5

The polarity of the induced voltage can be determined by using the left-hand generator rule

Accepted Answer

A. Yes

Question 6

Reversing the field or the current will reverse the force on the conductor

Accepted Answer

A. Yes

Question 7

The self-inductance of the coil may be defined as equal to the e.m.f. induced in volts when the current in the circuit changes at the rate of unit Weber turns

Accepted Answer

B. No

Question 8

Which circuit element(s) will oppose the change in circuit current ?

Accepted Answer

B. Inductance only

Question 9

A coil is wound on iron core which carries current I. The self-induced voltage in the coil is not affected by________________?

Accepted Answer

B. variation in voltage to the coil

Question 10

A crack in the magnetic path of an inductor will result in________________?

Accepted Answer

D. reduced inductance

Question 11

The co-efficient of coupling between two air core coils depends on____________?

Accepted Answer

C. mutual inductance and self inductance of two coils

Question 12

Current changing from 8 A to 12 A in one second induced 20 volts in a coil. The value of inductance is___________?

Accepted Answer

C. 5 H

Question 13

A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is___________?

Accepted Answer

B. 350 mH

Question 14

Find the force acting on a conductor 3m long carrying a current of 50 amperes at right angles to a magnetic field having a flux density of 0.67 tesla

Accepted Answer

A. 100 N

Question 15

An average voltage of 10 V is induced in a 250 turns solenoid as a result of a change in flux which occurs in 0.5 second. The total flux change is____________?

Accepted Answer

D. 0.02 Wb

Question 16

Two 300 uH coils in series without mutual coupling have a total inductance of___________?

Accepted Answer

A. 300 uH

Question 17

Which of the fpllowing inductor will have the least eddy current losses ?

Accepted Answer

A. Air core

Question 18

A 500 turns solenoid develops an average induced voltage of 60 V. Over what time interval must a flux change of 0.06 Wb occur to produce such a voltage ?

Accepted Answer

C. 0.5 s

Question 19

A coil with negligible resistance has 50V across it with 10 mA. The inductive reactance is_____________?

Accepted Answer

D. 5000 ohms

Question 20

A conductor carries 125 amperes of current under 60° to a magnetic field of 1.1 tesla. The force on the conductor will be nearly______________?

Accepted Answer

B. 120 N