Question

When the current in a conductor is doubled keeping other parameters constant, the heat energy produced will be _____ the initial value:

• A. is doubled
• B. becomes 4 times
• C. becomes 3 times
• D. is unaffected

Answer 1

The correct option is B

becomes 4 times

Heat produced in an electric circuit having a resistance R can be expressed as, $H=I^{2}Rt$

When the current in a conductor is doubled, keeping other parameters constant, the heat produced is $H^{\prime }={\left(2I\right)}^{2}Rt$

$H^{\prime }=4I^{2}Rt$ $=4H$

Thus if the current through a conductor is doubled keeping other parameters constant, then the heating effect of the current becomes 4 times the original.