When the time taken to complete a given amount of work increases, then,

Options

A. power increases
B. power decreases
C. energy increases
D. energy decreases

Answer

To solve the question, "When the time taken to complete a given amount of work increases, then," we need to analyze the relationship between work, time, and power.

### Step-by-Step Solution:

1. **Understanding the Concepts**:
- Work (W) is defined as the amount of energy transferred when a force is applied over a distance.
- Power (P) is defined as the rate at which work is done. It can be mathematically expressed as:
\[ P = \frac{W}{t} \]
where \( W \) is work done and \( t \) is the time taken to do that work.

2. **Given Information**:
- We are told that the amount of work is constant.
- The time taken to complete this work is increasing.

3. **Analyzing the Effect of Increasing Time**:
- If the time \( t \) increases while the work \( W \) remains constant, we can substitute this into the power formula:
\[ P = \frac{W}{t} \]
- As \( t \) increases, the denominator of the fraction increases, which means that the overall value of \( P \) (power) must decrease.

4. **Conclusion**:
- Therefore, when the time taken to complete a given amount of work increases, the power decreases.

### Final Answer:
- The correct option is: **Power decreases**.