Question

A sinusoidal ac current flows through a resistor of resistance R. If the peak current is$I _ { p }$, then the power dissipated is

• A. $I _ { p } ^ { 2 } R \cos \theta$
• B. $\frac { 1 } { 2 } I _ { p } ^ { 2 } R$
• C. $\frac { 4 } { \pi } I _ { p } ^ { 2 } R$
• D. $\frac { 1 } { \pi } I _ { p } ^ { 2 } R$

Answer 1

Answer: (B)

$\frac { 1 } { 2 } I _ { p } ^ { 2 } R$

Answer 2

Power $= I ^ { 2 } R = \left( \frac { I _ { p } } { \sqrt { 2 } } \right) ^ { 2 } R = \frac { I _ { p } ^ { 2 } R } { 2 }$