Question

On a heater coil it is written \(250\,V, 500\,W\). What is the resistance of this coil?

• A. \(62.5\,\Omega\)
• B. \(100\,\Omega\)
• C. \(200\,\Omega\)
• D. \(125\,\Omega\)

Hint:

Use \( R = \frac{V^2}{P} \) when voltage and power are given.

Answer 1

The Correct Option is D

Concept: \[ P = \frac{V^2}{R} \]

Step 1: Rearrange.
\[ R = \frac{V^2}{P} \]

Step 2: Substitute values.
\[ R = \frac{(250)^2}{500} = \frac{62500}{500} = 125\,\Omega \]