An electric lamp of 120 W is used for 8 hours per day. Calculate the units of energy consumed by the lamp in one day.

Options

A. 16.00 unit
B. 1.50 unit
C. 0.96 unit
D. 2.00 unit

Answer

To solve the problem of calculating the units of energy consumed by a 120 W electric lamp used for 8 hours per day, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Power of the Lamp**:
The power of the electric lamp is given as 120 W (watts).

2. **Identify the Time of Usage**:
The lamp is used for 8 hours per day.

3. **Use the Formula for Energy**:
The formula to calculate energy consumed is:
\[ \text{Energy} = \text{Power} \times \text{Time} \]

4. **Convert Time to Seconds**:
Since power is in watts (which is joules per second), we need to convert the time from hours to seconds:
\[ 8 \text{ hours} = 8 \times 3600 \text{ seconds} = 28800 \text{ seconds} \]

5. **Calculate the Energy in Joules**:
Now substitute the values into the formula:
\[ \text{Energy} = 120 \text{ W} \times 28800 \text{ seconds} = 3456000 \text{ joules} \]

6. **Convert Joules to Kilojoules**:
To convert joules to kilojoules, we divide by 1000:
\[ \text{Energy in kilojoules} = \frac{3456000 \text{ joules}}{1000} = 3456 \text{ kilojoules} \]

7. **Convert Kilojoules to Units**:
Since 1 unit of energy is equal to 1 kilowatt-hour (kWh), we can convert kilojoules to units:
\[ 1 \text{ kWh} = 3600 \text{ kJ} \]
Therefore, to find the number of units:
\[ \text{Units} = \frac{3456 \text{ kJ}}{3600 \text{ kJ/unit}} \approx 0.96 \text{ units} \]

### Final Answer:
The energy consumed by the lamp in one day is approximately **0.96 units**.

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