When a current is passed in a conductor, `3^(@)C` rise in temperature is observed. If the strength of current is made thrice, then rise in temperature will approximately be

Options

A. `36^(@)C`
B. `27^(@)C`
C. `186^(@)C`
D. `9^(@)C`

Answer

B

Explanation

`H=I^(2)Rt=mc Delta theta`
`therefore" "Delta prop I^(2)`
Hence `(Deltatheta_(2))/(Deltatheta_(1))=((I_(2))/(I_(1)))^(2) or (Deltatheta_(2))/(3)=((3I)/(I))^(2)`
`or Deltatheta_(2)=9xx3=27^(@)C`