Question

Three equal resistors connected in series across a source of emf together dissipate 10 W power. The power dissipated if the same resistors are connected in parallel is

• A. 70W
• B. 80W
• C. 90W
• D. 100W

Answer 1

The correct option is C 90W

Case 1
$P=\frac{V^2}{3R}=10$ Watt
Case 2
$P=\frac{{3V}^2}{R}$
$=9\left(\frac{V^2}{3R}\right)$
$=$ 90 W