Electricity

Step 1: Applying Ohm's Law.
Ohm’s law states that the current is given by the total emf divided by the total resistance in the circuit:

Step 2: Total resistance in the circuit.
The total resistance in the circuit is the sum of the resistance and the internal resistance . Therefore, the total resistance is:

Step 3: Finding the current.
Now, using Ohm’s law:

Final Answer: .

We use the formula for electrical power: where is power, is current, and is resistance. We also know the relationship between power, voltage, and current: where is voltage.

Step 1: Calculate the voltage.
Given that and , we can calculate the voltage:

Step 2: Conclusion.
Thus, the potential across the electric iron is 10V.

Final Answer: 10V.