In an electric heater with a constant coil resistance, through which a direct current flows, the amount

In an electric heater with a constant coil resistance, through which a direct current flows, the amount of heat Q is released during time t. How will the amount of heat released in the heater change if the current and time t are doubled?

The amount of heat released depends on the power of the heater and on the heating time.

The power of the heater is directly proportional to the current and voltage. To change the current strength by half and at the same time without changing the resistance of the spiral according to Ohm’s law, it is necessary to double the voltage. Accordingly, the power will quadruple. Add the time doubled here and, as a result, we get an eight-fold increase in the released heat.