Q 12-03-044NEETJEE MainMedium
A heater coil boils a certain amount of water in $10$ min. If the coil is cut in half and one half is used on the same supply, the same water boils in
Answer: (A) $5$ min
Half the length gives half the resistance, so $P = \dfrac{V^2}{R}$ doubles and the time halves: $5$ min.
Solution by Sreeraj P, M.Sc Physics