Question

A heater is designed to operate with a power of $100$w on $100$v line.It is connected to resistance of $10\Omega$. what is power output of heater?

Answer 1

Given maximum power of the heater $P_{max}=100W$

Voltage $V=100V$ and resistance offered to the heater $R_1=10\Omega$ and $R_2=10\Omega$

Now from figure we observe that both the resistors are connected in parallel, thus the equivalent resistance $R_{eq}=\frac{R_1{R}_2}{R_1+R_2}=5\Omega$

Also we know Power$P=VI$ -------(A)where V=voltage and I=current

Again $V=IR$

$I=\frac{V}{R}$

Putting the value of I in A we get,

$P=\frac{V^2}{R_{eq}}=\frac{100\times 100}{5}=2000W$