Magnetism and Electromagnetism
A permeable substance is one

Through which the magnetic lines of force can pass very easily
Which is a good conductor
Which is a strong magnet
Which is a bad conductor

ANSWER DOWNLOAD EXAMIANS APP

Magnetism and Electromagnetism
Main causes of noisy solenoid are

uneven bearing surface, caused by dirt or uneven wear between moving and stationary parts
strong tendency of fan out of laminations at the end caused by repulsion among magnetic lines of force
None of these
Both of the listed here

ANSWER DOWNLOAD EXAMIANS APP

Magnetism and Electromagnetism
The magnetomotive force is

The flow of an electric current
The sum of all currents embraced by one line of magnetic field
The voltage across the two ends of exciting coil
The passage of magnetic field through an exciting coil

ANSWER DOWNLOAD EXAMIANS APP

Magnetism and Electromagnetism
A certain amount of current flows through a ring shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil?

Increases
Decreases
Remains same
First increases and then decreases depending on the depth of iron in¬sertion

ANSWER DOWNLOAD EXAMIANS APP