Temperature of a conductor increases by `5^(@)`C passing electric current for same time. The increase in its temperature when double current is passed through 1he same conductor the same time is ..... `""^(@)C`.

Options

A. 10
B. 12
C. 16
D. 20

Answer

D

Explanation

20
` H = (I^(2) Rt)/(J)`
ms `Delta theta = (I^(2) Rt)/(J) `
`therefore Delta theta prop I^(2)`
`therefore Delta theta_(1) prop I_(1)^(2)`
`therefore Delta theta_(2) prop I_(2)^(2) `
` therefore (Delta theta_(2))/(Delta theta_(1)) = ((I_(2))/(I_(1)) )^(2) `
`therefore Delta theta_(2) = ((I_(2))/(I_(1)))^(2) Delta theta_(1)`
Now `I_(2) = 2I_(1)`
`therefore Delta theta_(2) = ((2I_(1))/(I_(1)))^(2) xx 5 `
`therafore Delta theta_(2) = 20""^(@)C`