A `5^(@)C` rise in the temperature is observed in a conductor by passing some current. When the current is doubled, then rise in temperature will be equal to

Options

A. `16^(@)`C
B. `10^(@)` C
C. `20^(@)`C
D. `12^(@)` C

Answer

C

Explanation

On increasing the current twice, the rise in temperature will be four times.
As `H prop i^(2)` and `H prop T` of current is doubled, then
`H = 4H_(1)` and `T_(2) = 4T_(1) = 20^(@) C`