Question

One heater uses 490 W of power when connected by itself to a battery. Another heater uses 250 W of power when connected by itself to the same battery. How much total power do the heaters use when they are both connected in series across the battery?

Answer 1

Answer:

Power will be 166.66 watt when the heater are connected in series

Explanation:

We have given power of the first heater $P_1$ = 490 watt

And power of the second heater $P_2$ = 250 watt

We know that in series connection potential difference will be same

So let the potential difference is v

Power is given by $P=\frac{V^2}{R}$

So $490=\frac{V^2}{R_1}$

$R_1=\frac{V^2}{490}=0.0020V^2$

Similarly $R_2=\frac{V^2}{250}=0.04V^2$

As resistances are connected in series so equivalent resistance $R=R_1+R_2=0.0020V^2+0.04V^2=0.006V^2$

So power $P=\frac{V^2}{R}=\frac{V^2}{0.006V^2}=166.66Watt$