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A heater of 1 kW and a tungsten bulb of ...

A heater of 1 kW and a tungsten bulb of 100 W both marked for 220 V.
The resistance of heater is:

A

50.4 `Omega`

B

51 `Omega`

C

48.4 `Omega`

D

46 `Omega`

Text Solution

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The correct Answer is:
To find the resistance of the heater, we can use the formula for electrical power, which is given by: \[ P = \frac{V^2}{R} \] Where: - \( P \) is the power (in watts), - \( V \) is the voltage (in volts), - \( R \) is the resistance (in ohms). ### Step 1: Identify the given values From the question, we know: - Power of the heater, \( P = 1 \text{ kW} = 1000 \text{ W} \) - Voltage, \( V = 220 \text{ V} \) ### Step 2: Rearrange the formula to find resistance We need to find the resistance \( R \). Rearranging the formula gives us: \[ R = \frac{V^2}{P} \] ### Step 3: Substitute the values into the formula Now, we can substitute the known values into the rearranged formula: \[ R = \frac{(220 \text{ V})^2}{1000 \text{ W}} \] ### Step 4: Calculate \( V^2 \) Calculating \( (220)^2 \): \[ 220^2 = 48400 \] ### Step 5: Substitute \( V^2 \) back into the equation Now substitute \( V^2 \) back into the equation for resistance: \[ R = \frac{48400}{1000} \] ### Step 6: Perform the division Now, perform the division: \[ R = 48.4 \text{ ohms} \] ### Conclusion The resistance of the heater is \( 48.4 \text{ ohms} \).

To find the resistance of the heater, we can use the formula for electrical power, which is given by: \[ P = \frac{V^2}{R} \] Where: - \( P \) is the power (in watts), ...
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