Question

The heating element of a hair drier dissipates $1500W$when connected to a $120V/60Hz$power line. What is its resistance?

Short answer

In a circuit power is dissipated by resistance only.

Step-by-step solution

Given information

We have given the values ,

$$\begin{gathered} P=1500W \\ V=120V \\ f=60Hz \end{gathered}$$

Calculation

In a circuit power is dissipated by resistance elements only.

So using formula of power dissipation $i.e$

$P=\frac{V^2}{R}$

Substituting given values in above equation, we get

localid="1649924337177" $$\begin{gathered} 1500={\left(120\right)}^2/R \\ R={\left(120\right)}^2/1500 \\ R=9.6\Omega \end{gathered}$$

Hence, required value of resistance is localid="1649924341773" $9.6\Omega$