Question

r.m.s. value of alternating current in a circuit is 4 A and power factor is 0.5. If the power dissipated in the circuit is 100W, then the peak value of voltage in the circuit is

• A. 50 volt
• B. 70 volt
• C. 35 volt
• D. 100 volt

Answer 1

Answer: (B)

70 volt

Answer 2

$P = V _ { r m s } i _ { r m s } \cos \phi$ ⇒ $100 = V _ { r m s } \times 4 \times 0.5$

⇒ $V _ { r m s } = 50 \mathrm {~V}$ so