Question

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is ______.

विकल्प

• `1/25`

• `1/5`

• 5

• 25

Answer 1

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is 25.

Explanation:

The resistance is cut into five equal parts, which means that the resistance of each part is `"R"/5`.

We know that each part is connected to each other in parallel, hence the equivalent resistance can be calculated as follows:

`1/"R'" = 5/"R" + 5/"R" + 5/"R" + 5/"R" + 5/"R"`

= `(5 + 5 + 5 + 5 + 5)/"R"`

= `25/"R"`

`"R"/"R'"` = 25

The ratio of `"R"/"R'"` is 25.