A series LCR circuit has and is connected to a (rms) AC mains

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A series LCR circuit has

R = 20\,\Omega

and is connected to a

100\,\text{V}

(rms) AC mains. Before tuning, the rms current in the circuit is

2\,\text{A}

. After adjusting the frequency to resonance, the percentage rise in rms current is closest to (a)

60\%

(b)

150\%

(c)

250\%

(d)

100\%