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 solve the problem of finding the power consumed by a light bulb rated at 200 W and 220 V when supplied with 200 V, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the given values:**
- Rated Power (P) = 200 W
- Rated Voltage (V_rated) = 220 V
- Supply Voltage (V_supply) = 200 V

2. **Calculate the resistance of the bulb:**
The resistance (R) of the bulb can be calculated using the formula:
\[ R = \frac{V_{rated}^2}{P} \]
Substituting the values:
\[ R = \frac{220^2}{200} = \frac{48400}{200} = 242 \, \Omega \]

3. **Calculate the power consumed at the supply voltage:**
Now, we can find the power consumed (P_consumed) when the supply voltage is 200 V using the formula:
\[ P_{consumed} = \frac{V_{supply}^2}{R} \]
Substituting the values:
\[ P_{consumed} = \frac{200^2}{242} = \frac{40000}{242} \approx 165.28 \, W \]

4. **Conclusion:**
The power consumed by the bulb when the supply voltage is 200 V is approximately 165.28 W.