Top 250+ Solved Electromagnetic Theory MCQ Questions Answer
Q. 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
a. 50 N
b. 120 N
c. 240 N
d. 480 N
Q. The co-efficient of coupling between two air core coils depends on
a. self-inductance of two coils only
b. mutual inductance between two coils only
c. mutual inductance and self inductance of two coils
d. none of the above
Q. An average voltage of 10 V is induced in a 250 turns solenoid as a result of a change influx which occurs in 0.5 second. The total flux change is
a. 20 Wb
b. 2 Wb
c. 0.2 Wb
d. 0.02 Wb
Q. Which of the fpllowing inductor will have the least eddy current losses ?
a. Air core
b. Laminated iron core
c. Iron core
d. Powdered iron core
Q. A coil induces 350 mV when the current changes at the rate of 1 A/s. The value ofinductance is
a. 3500 mH
b. 350 mH
c. 250 mH
d. 150 mH
Q. Two 300 uH coils in series without mutual coupling have a total inductance of
a. 300 uH
b. 600 uH
c. 150 uH
d. 75 uH
Q. Current changing from 8 A to 12 A in one second induced 20 volts in a coil.The value of inductance is
a. 5 mH
b. 10 mH
c. 5 H
d. 10 H
Q. Which circuit element(s) will oppose the change in circuit current ?
a. Resistance only
b. Inductance only
c. Capacitance only
d. Inductance and capacitance
Q. A crack in the magnetic path of an inductor will result in
a. unchanged inductance
b. increased inductance
c. zero inductance
d. reduced inductance
Q. A coil is wound on iron core which carries current I. The self-induced voltage in the coilis not affected by
a. variation in coil current
b. variation in voltage to the coil
c. change of number of turns of coil
d. the resistance of magnetic path
Q. The polarity of the induced voltage can be determined by using the left-hand generatorrule.
a. Yes
b. No
c. none
d. none
Q. Increasing the field or increasing the current will decrease the force on the conductor.
a. Yes
b. No
c. none
d. none
Q. Reversing the field or the current will reverse the force on the conductor.
a. Yes
b. No
c. none
d. none