Question

An electric bulb is designed to consume 55w when operated at 110v

Answer 1

Power = 55W, Voltage = 110V, Resistance = V2/P

= (110 x 110)/55

= 220Ω

frequency (f) = 50Hz,

ω= 2πf

= 2π × 50

= 100π

Current in the circuit

Voltage drop across the resistor

=> (220)2 + (100πL)2 = (440)2

=> 48400 + 104π2L2 = 193600

104π2L2 = 193600 – 48400

=> L = 1.2135

≈ 1.2Hz