Identify the relevant formula

The relationship between power $P$, voltage $V$, and resistance $R$ for an electrical appliance is given by the formula $P = \frac{V^2}{R}$. We need to calculate $R$.

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

Substitute the given values

Substitute the given values into the rearranged formula: $V = 200$ V and $P = 100$ W.

$R = \frac{200°2}{100}$

Calculate the final resistance

Perform the arithmetic: $200°2 = 40,000$. Then, $40,000 / 100 = 400$.

$R = \frac{40000}{100} = 400 \ \Omega$