Question

A cylindrical conductor of length l and uniform area of cross-section A has resistance R. Another conductor of length 2l and resistance R of the same material has an area of cross-section:

Options

• `"A"/2`

• `(3"A")/2`

• 2A

• 3A

Answer 1

2A

Explanation:

P = `"RA"/"l"`

When Length doubles

P= `"RA"/(2"l")`

`"RA"/"l" = "RA"/(2"l")`

A = 2A