In measuring electric energy, 1 kWh is equal to

Options

A. `3.6xx10^(4)` J
B. `3.6xx10^(6)` J
C. `7.3xx10^(6)` J
D. None of these

Answer

To solve the problem of converting 1 kilowatt hour (kWh) to joules, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Units**:
- 1 kilowatt (kW) is equal to 1000 watts (W).
- 1 hour (h) is equal to 3600 seconds (s).

2. **Convert Kilowatts to Watts**:
- Since 1 kW = 1000 W, we can express 1 kWh in terms of watts:
\[ 1 \text{ kWh} = 1000 \text{ W} \times 1 \text{ hour} \]

3. **Convert Hours to Seconds**:
- We know that 1 hour = 3600 seconds. Therefore, we can rewrite the equation:
\[ 1 \text{ kWh} = 1000 \text{ W} \times 3600 \text{ s} \]

4. **Calculate the Energy in Joules**:
- Since 1 watt is equal to 1 joule per second (1 W = 1 J/s), we can express the energy in joules:
\[ 1 \text{ kWh} = 1000 \text{ J/s} \times 3600 \text{ s} = 1000 \times 3600 \text{ J} \]

5. **Perform the Multiplication**:
- Now, calculate \(1000 \times 3600\):
\[ 1000 \times 3600 = 3,600,000 \text{ J} \]

6. **Express in Scientific Notation**:
- Finally, we can express 3,600,000 joules in scientific notation:
\[ 3,600,000 \text{ J} = 3.6 \times 10^6 \text{ J} \]

### Final Answer:
Thus, 1 kilowatt hour (kWh) is equal to \(3.6 \times 10^6\) joules (J).

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