Question

The magnetic flux through a loop placed in a magnetic field can be changed by changing:

Options

• area of the loop only.

• the value of magnetic field only.

• orientation of the loop in the magnetic field only.

• any one or more of the factors given in the above options.

Answer 1

Any one or more of the factors given in the above options.

Explanation:

Magnetic flux through a loop is given by:

Φ = BA cos θ

Where:

B = magnetic field strength

A = area of the loop

θ = angle between magnetic field and area vector

If the area A changes, the flux changes since:

Φ ∝ A

If the magnetic field strength changes:

Φ ∝ B

So flux changes.

If the loop is rotated, the angle θ changes. Since:

Φ ∝ cos θ

Flux also changes.

Magnetic flux depends on all three factors: area, magnetic field, and orientation. Changing any one (or more) of them changes flux.