Question

Two electric lamps each of 100 watts 220 V are connected in series to a supply of 220 volts. The power consumed would be -

• A. 100 watts
• B. 200 watts
• C. 25 watts
• D. 50 watts

Answer 1

The correct option is D 50 watts

Let resistance of lamp $=R$
$R=\frac{(220{)}^2}{100}[UsingP=\frac{V^2}{R}]$
[equivalent resistance in series $=2R]$
Power consumed $=\frac{(220{)}^2}{2R}=\frac{(220{)}^2}{2\times (220{)}^2}\times 100=50watt$