Question

When a heating coil is immersed in melting ice, the ice melts at a rate of 10grams per minute. If the current in the coil is doubled while its resistance remains constant, the mass of ice that will melt per minute is?

Answer 1

$Q_1=\lambda m,$

$Q_2=I^2Rt,$

$Q_1=Q_2,$

$\lambda m=I^2Rt,$

$m\sim I^2,$

$m_2=m_1\frac{(2I)^2}{I^2}=4m_1=40~g.$