Heater of an electric kettle is made of a wire of length L and diameter d. It takes 4 minutes to raise the temperature of 0.5 kg water by 40 K. This heater is replaced by a new heater having two wires of the same material, each of length L and diameter 2d. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by 40K?JEE Advanced 2014 (Paper 1)A4 if wires are in parallelB2 if wires are in seriesC1 if wires are in seriesD0.5 if wires are in parallel.

An electric heater has two coils. When a current is passed through one of them, water in heater boils in 3 minutes and when current is passed through other one, the water boils in 4 minutes. Then  One/More correct answer(s)A.If both the coils are joined in series, the water in heater boils in 7 minutesB.If both the coils are connected in parallel, the water in heater boils in 127127 minutesC.The resistances of two coils are in the ratio 3 : 4D.If both the coils are joined in series, the water in heater boils in 3.5 minutes

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be :(a) 1 : 2(b) 2 : 1(c) 1 : 4(d) 4 : 1

An electric kettle has two heating coils. When one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same amount of water boils in 10 minutes. If the two coils are connected in parallel then same amount of water will boil in time :-

2. A kettle containing water at 30 °C is heated to 100°C. Find the change in temperature in: i) °C ii) K​

A coil of copper wire has a resistance of 40 W at 20°C and the temperature coefficient of the wire is 0.004 /°C at 20°C. Determine the temperature of the wire when the resistance is 46 W.