Paper 1 Electromagnetic Induction Answers

Q	Answer	Reason
1	A	Flux is $BA\cos \theta$ with area-normal convention.
2	A	Flux linkage is turns times flux.
3	A	Faraday law: $\mathcal{E}=-d(N\Phi )/dt$.
4	B	Minus sign encodes Lenz law.
5	B	Opposition prevents free energy creation.
6	B	Constant flux linkage gives zero induced emf.
7	A	For mutually perpendicular rod, field and velocity.
8	A	$\mathcal{E}\propto N$.
9	A	They circulate within conducting material.
10	A	Dissipative heating and braking are common effects.
11	A	Larger rate of flux change.
12	B	No change in flux linkage.
13	A	Magnetic flux is measured in weber.
14	A	Flux linkage has unit Wb turn.
15	B	Lenz law.
16	A	The induced current produces magnetic force opposing motion.
17	A	$
18	B	Gradient of flux-linkage graph gives induced emf.
19	A	Transformer action is mutual induction.
20	A	An emf can exist as work per unit charge even before current flows.