Electromagnetic Induction MCQ Part 1

Electromagnetic Induction MCQ Part 1

Q1. Mutually inductance between two magnetically-coupled coils depends on

A.  permeability of the core
B.  the number of their turns
C.  cross-sectional area of their common core
D.  all of the above

Ans. D

Q2. An e.m.f. of 16 volts is induced in a coil of inductance 4 H. The rate of change of current must be

A.  64 A/s
B.  32 A/s
C.  16 A/s
D.  4 A/s

Ans. D

Electromagnetic Induction MCQ Part 1

Q3. 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

Ans. C

Q4. A crack in the magnetic path of an inductor will result in

A.  unchanged inductance
B.  increased inductance
C.  zero inductance
D.  reduced inductance

Ans. D

Electromagnetic Induction MCQ Part 1

Q5. Higher the self-inductance of a coil,

A.  lesser its weher-turns
B.  lower the e.m.f. induced
C.  greater the flux produced by it
D.  longer the delay in establishing steady current through it

Ans. D

Q6. A laminated iron core has reduced eddy-current losses because

A.  more wire can he used with less D.C. resistance in coil
B.  the laminations are insulated from each other
C.  the magnetic flux is concentrated in the air gap of the core
D.  the laminations are stacked vertically

Ans. B

Electromagnetic Induction MCQ Part 1

Q7. The core of a coil has a length of 200 mm. The inductance of coil is 6 mH. If the core length is doubled, all other quantities, remaining the same, the inductance will be

A.  3 mH
B.  12 mH
C.  24 mH
D.  48 mH

Ans. A

Q8. 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

A.  20 Wb
B.  2 Wb
C.  0.2 Wb
D.  0.02 Wb

Ans. D

Electromagnetic Induction MCQ Part 1

Q9. In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will

A.  increase
B.  decrease
C.  remain the same
D.  initially increase and then decrease

Ans. C

Q10. The co-efficient of self-inductance for a coil is given as

A.  NI/Φ
B.  NΦ/I
C.  NI2/Φ
D.  NΦ/I2

Ans. C