Electricity and Magnetism AFCAT Questions

Electricity and Magnetism MCQ Questions

13.
The magnetic field of a magnietized iron bar when strongly heated
A.
Becomes weaker
B.
Becomes stronger
C.
constant
D.
Reverses its direction
ANSWER :
A. Becomes weaker
14.
The average velocity attained by the electrons moving inside a conductor in the presence of an external electric field is known as
A.
Conductor
B.
Resistor
C.
Drift Velocity
D.
None of the above
ANSWER :
C. Drift Velocity
15.
The heating element of an electric iron is made up of ______
A.
Copper
B.
aluminium
C.
iron
D.
nichrome
ANSWER :
D. nichrome
16.
The magnitude of the drift velocity per unit electric field is called as
A.
Velocity
B.
Mobility
C.
Electric density
D.
None of the above
ANSWER :
B. Mobility
17.

The SI units of Mobility is

A.

A/m2

B.

m2/(V.s)

C.

cm2

D.

m2

ANSWER :

B. m2/(V.s)

18.
A electric bell depends for its action on
A.
a parmanent magnet
B.
a gong
C.
an electromagnet
D.
a hammer
ANSWER :
C. an electromagnet