Question

A $3^{0}C$ rise of temperature is observed in a conductor by passing a certain current. When the current is doubled ,the rise of temperature will be

• A. ${15}^{0}C$
• B. ${12}^{0}C$
• C. $9^{0}C$
• D. $3^{0}C$

Answer 1

The correct option is B ${12}^{0}C$

We know that heat $H=i^{2}Rt$ so $H\propto i^2$
So when current i is double, heat will four times increase.
As heat is proportional to change in temperature i.e, $H\propto \Delta T$ so the rise in temperature will be ${12}^{o}C$.