Question

An ac supply gives 30 V r.m.s. which passes through a $10\Omega$ resistance. The power dissipated in it is

• A. $90\sqrt{2}W$
• B. $90W$
• C. $45\sqrt{2}W$
  
• D. $45W$

Answer 1

The correct option is B $90W$

$P=\frac{V_{rms}^2}{R}=\frac{(30{)}^2}{10}=90W$