An electric bulb rated for `500 W` at `100 V` is used in a circuit having a `200 V` supply. The reistance `R` that must be put in series with bulb, so that the bulb delivers `500 `W is ……….`Omega`.

Explanation

To solve the problem step by step, we need to determine the resistance that must be placed in series with the bulb rated at 500 W and 100 V when connected to a 200 V supply.

### Step 1: Calculate the resistance of the bulb
The resistance \( R_b \) of the bulb can be calculated using the formula:
\[ R_b = \frac{V^2}{P} \]
where \( V \) is the voltage rating of the bulb (100 V) and \( P \) is the power rating (500 W).
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