CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1 · Question Q18

A direct current of 5\text{ A} dissipates heat in a given resistor at the same rate as a sinusoidal alternating current flowing through the same resistor. What is the root mean square value of the alternating current.

1. (A)\sqrt{2}\text{ A}
2. (B)5\text{ A}
3. (C)5\sqrt{2}\text{ A}
4. (D)\frac{5}{\sqrt{2}}\text{ A}