Calculate the value of heat produced by the bulb in 1 second if the potential difference is 20 V and resistance is 4 ohm ?

Options

A. 100 J
B. 270J
C. 187J
D. 670J

Explanation

To calculate the heat produced by the bulb in 1 second, we can use the formula for heat produced in an electrical circuit:

\[ H = \frac{V^2 \cdot t}{R} \]

Where:
- \( H \) is the heat produced (in joules),
- \( V \) is the potential difference (in volts),
- \( t \) is the time (in seconds),
- \( R \) is the resistance (in ohms).

### Step-by-Step Solution:

1. **Identify the given values**:
- Potential difference \( V = 20 \, \text{V} \)
- Resistance \( R = 4 \, \Omega \)
- Time \( t = 1 \, \text{s} \)

2. **Substitute the values into the formula**:
\[ H = \frac{(20)^2 \cdot 1}{4} \]

3. **Calculate \( V^2 \)**:
\[ V^2 = 20^2 = 400 \]

4. **Substitute \( V^2 \) back into the equation**:
\[ H = \frac{400 \cdot 1}{4} \]

5. **Perform the division**:
\[ H = \frac{400}{4} = 100 \]

6. **Final result**:
The heat produced by the bulb in 1 second is \( 100 \, \text{J} \).

### Conclusion:
The value of heat produced by the bulb in 1 second is **100 joules**.