A light bulb has the rating 200 W 220 V.
If the supply voltage is 200 V, then find power consumed by the bulb.

Answer

To find the power consumed by a light bulb rated at 200 W and 220 V when the supply voltage is 200 V, we can follow these steps:

### Step 1: Calculate the resistance of the bulb
The resistance \( R \) of the bulb can be calculated using the formula:
\[ R = \frac{V^2}{P} \]
where \( V \) is the rated voltage (220 V) and \( P \) is the rated power (200 W).

Substituting the values:
\[ R = \frac{(220)^2}{200} = \frac{48400}{200} = 242 \, \Omega \]

### Step 2: Calculate the power consumed at the supply voltage of 200 V
Now that we have the resistance, we can calculate the power consumed \( P' \) when the supply voltage is 200 V using the formula:
\[ P' = \frac{V'^2}{R} \]
where \( V' \) is the supply voltage (200 V).

Substituting the values:
\[ P' = \frac{(200)^2}{242} = \frac{40000}{242} \approx 165.29 \, W \]

### Final Answer
The power consumed by the bulb when the supply voltage is 200 V is approximately **165 W**.

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