`20` coulomb charge flows through 15 volt battery in a certain interval. Find work done (in J) by the battery?

Answer

To find the work done by a battery when a charge flows through it, we can use the formula:

\[ W = V \times Q \]

where:
- \( W \) is the work done (in joules),
- \( V \) is the voltage (in volts),
- \( Q \) is the charge (in coulombs).

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Charge \( Q = 20 \) coulombs
- Voltage \( V = 15 \) volts

2. **Use the Formula for Work Done**:
- Substitute the values into the work done formula:
\[ W = V \times Q \]

3. **Calculate the Work Done**:
- Substitute the known values:
\[ W = 15 \, \text{volts} \times 20 \, \text{coulombs} \]
- Perform the multiplication:
\[ W = 300 \, \text{joules} \]

4. **Final Result**:
- The work done by the battery is \( 300 \) joules.