Physics

Grade-9

Easy

Question

# An electrician installs patio lights in a back yard. Which of the following will decrease the efficiency of the wiring system to the back yard?

1- Bury the extension cord very deep down underground.

2- Use a short extension cord.

3- Use a long extension cord.

4- Use compact fluorescent light bulbs

- 1 and 2
- 1 and 3
- 2 and 4
- 3 and 4

Hint:

### 1 and 3

## The correct answer is: 1 and 3

### It is never advisable and it is not designed to bury extension cord deep under the ground .

Using long extension cord can affect efficiency as it has resistance. So, more length will lead to more resistance.

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