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?

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

ANSWER DOWNLOAD EXAMIANS APP

Magnetism and Electromagnetism
Main causes of noisy solenoid are

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

ANSWER DOWNLOAD EXAMIANS APP

Magnetism and Electromagnetism
Out of the following statements, concerning an electric field, which statement is not true?

An electric field is defined as a point in space at which an electric charge would experience a force
Unit field intensity in the exertion of a force of one newton on a charge of one coulomb
The electric field intensity at a point is numerically equal to the force exerted upon a charge placed at that point
The electric intensity is a vector quantity

ANSWER DOWNLOAD EXAMIANS APP