An ac ammeter is used to measure currnet in a circuit. When a given direct current passes through the circuit. The ac ammeter reads 3 A. When another alternating current passes through the circuit, the ac ammeter reads 4A. Then find the reading of this ammeter (inA), if dc and ac flow through the circuit simultaneously.

Options

A. 3A
B. 4A
C. 7A
D. 5A

Answer

D

Explanation

Total heat produced per second
`I^(2) R = (3)^(2) R + (4^(2)) R rArr I = 5A `