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 current is
Select an Answer
The correct answer is . In this series circuit with just one resistor, the emf across the battery is equal to the voltage across the resistor, so if the emf is doubled so is . The current in the resistor is given by Ohm’s law, , so if is doubled while the resistance remains constant, then is also doubled.