Top 350+ Solved Electromagnetics MCQ Questions Answer
Q. In case all the flux from the current in coil 1 links with coil 2, the co-efficient of couplingwill be
a. 2.0
b. 1.0
c. 0.5
d. zero
Q. A coil with negligible resistance has 50V across it with 10 mA. The inductive reactanceis
a. 50 ohms
b. 500 ohms
c. 1000 ohms
d. 5000 ohms
Q. Lenz's law is a consequence of the law of conservation of
a. induced current
b. charge
c. energy
d. induced e.m.f.
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