A single resistor is connected to a battery as shown above. The current is and the power dissipated as heat is . The circuit is changed by doubling the emf of the battery while is kept constant.
After the change, the power dissipated in is
Select an Answer
The correct answer is . The power dissipated by a resistor is given by , where is the current in the resistor and is the voltage across it. When used in combination with Ohm’s law, the power can also be written as , where is the resistance. If the emf is doubled while remains the same, is quadrupled.