Question

Is it possible to operate two 1250 W hair dryers on a 120 V circuit without blowing a 20 amp fuse?

Answer 1

Given:

The power of each hair dryer is,

$P=1250\text{ W}$

The potential across the circuit is,

$V=120\text{ V}$

The fuse has current

$i=20\text{ A}$

To find:

Is it possible to use that fuse or not

Explanation:

The power for two heaters is,

$\begin{gathered} P^{\prime}=2P \\ =2\times1250 \\ =2500\text{ W} \end{gathered}$

The current for this power is,

$\begin{gathered} I=\frac{P^{\prime}}{V} \\ =\frac{2500}{120} \\ =20.8\text{ A} \end{gathered}$

Here, we see the current for the dryers is greater than the fuse's current.

Hence, it is not possible to use the given fuse.