Question

An Electric Bulb Of Resistance $200\Omega$ Draws A Current Of $1$ Ampere. Calculate The Power Of The Bulb The Potential Difference At Its Ends And The Energy In Kwh Consumed Burning It For $5\mathrm{H}$.

Answer 1

Step 1: Find the power of the bulb.

$P=I^{2}R$

Where $P$ is power, $I$ is the current drawn and $R$ is the Resistance.

$\begin{array}{c}P=1^2\times 200\\ =1\times 200\\ =200 \mathrm{W}\end{array}$

Step 2: Find the energy consumed by the bulb in 5h.

$\begin{array}{c}\mathrm{Energy}=\mathrm{Power}\times \mathrm{Time}\\ =200\times 5\\ =1000 \mathrm{WH}\\ =1\mathrm{KWH}\end{array}$

Hence the energy in KWH consumed by the bulb in 5H is $1\mathrm{KWH}$.