Paper 1 Alternating Current Generators Answers

Q	Answer	Reason
1	B	Generator converts mechanical work to electrical energy.
2	A	Rotating coil changes flux linkage.
3	A	Faraday induction.
4	B	Slip rings connect to rotating coil without commutation.
5	A	Area-normal angle changes sinusoidally.
6	B	$
7	A	Gradient of flux is zero at maximum flux.
8	A	${\mathcal{E}}_0=NBA\omega$.
9	A	Peak emf proportional to angular speed.
10	A	One cycle per rotation for simple two-pole generator.
11	A	Commutator reverses connections to make unidirectional output.
12	A	The gradient changes sign.
13	A	Peak emf proportional to $B$.
14	A	Flux amplitude $BA$ increases.
15	A	Ideal uniform rotation gives sinusoidal emf.
16	A	Derivative of cosine is sine with quarter-cycle phase shift.
17	A	Area normal parallel to field.
18	B	Area normal perpendicular to field.
19	A	All increase $NBA\omega$.
20	A	Conservation of energy.