Question

Magnetic flux may be varied by

Answer 1

Magnetic flux

$\Phi=B\cdot A\cdot \cos\alpha$

You can change $\Phi$ by changing $B$ and $A$ or $\alpha$ .

Also, $B$ can be altered by changing the current.

If $B=const$ and $A=const$ then $\Phi$ changes from $B\cdot A (\alpha=0°)$ to $-B\cdot A (\alpha=180°)$.