Question

A bulb rate $220V,100W$ is connected across $110V$ line. The power dissipated will be

• A. $100W$
• B. $75W$
• C. $52W$
• D. $25W$

Answer 1

The correct option is D $25W$

$\text{Power}=\frac{v^2}{R}100=\frac{(220{)}^2}{R}R=484\Omega$

$\text{Power}=\frac{v^2}{R}$

$\text{Power}=\frac{(110{)}^2}{484}$

$\text{Power}=\frac{12100}{484}$

$\text{Power}=\frac{100}{4}=25W$