# Worksheet: Electromotive Force and Internal Resistance

In this worksheet, we will practice relating the electromotive force (emf) of a battery to its terminal voltage and its internal resistance.

Q1:

A battery has an electromotive force of 2.50 V. The terminal voltage of the battery is 2.42 V when it is connected to a circuit and there is a current of 435 mA in the circuit. What is the internal resistance of the battery?

Q2:

Which of the following statements is a correct description of the terminal voltage of a battery?

• AThe terminal voltage of a battery is the voltage required to overcome its internal resistance.
• BThe terminal voltage of a battery is the voltage of the battery when it is fully discharged.
• CThe terminal voltage of a battery is the voltage that it applies across a circuit to which it is connected.
• DThe terminal voltage of a battery is the potential difference across its terminals when it is not producing any current.

Q3:

Which of the following statements is a correct description of the lost voltage of a battery?

• AThe lost voltage of a battery is the voltage of the battery when it is fully discharged.
• BThe lost voltage of a battery is the potential difference across its terminals when it is not producing any current.
• CThe lost voltage of a battery is the voltage that it applies across a circuit that it is connected to.
• DThe lost voltage of a battery is the voltage required to overcome its internal resistance.

Q4:

Which of the following statements correctly relates the electromotive force of a battery to the current through the battery, the terminal voltage of the battery, and the internal resistance of the battery?

• A
• B
• C
• D
• E

Q5:

Which of the following statements is a correct description of the electromotive force (emf) of a battery?

• AThe emf of a battery is the voltage that it applies across a circuit to which it is connected.
• BThe emf of a battery is the current within the battery.
• CThe emf of a battery is the potential difference across its terminals when it is not producing any current.
• DThe emf of a battery is the voltage required to overcome its internal resistance.

Q6:

A circuit is powered by a battery with a terminal voltage of 2.5 V. The circuit has a resistance of 3.5 Ω and the battery has an internal resistance of 0.65 Ω. What is the electromotive force of the battery?

Q7:

A battery with an electromotive force of 4.50 V is connected to a circuit with a resistance of 2.75 Ω. The current in the circuit is 1.36 A. What is the internal resistance of the battery?

Q8:

A circuit is powered by a battery with an electromotive force of 3.6 V. The circuit has a resistance of 5.5 Ω and the battery has an internal resistance of 0.75 Ω. What is the terminal voltage of the battery?

Q9:

A battery has an internal resistance of 0.48 Ω. The electromotive force of the battery is 3.5 V. What is the terminal voltage of the battery when it is connected to a circuit and there is a current of 650 mA in the circuit?

Q10:

A battery is connected to a circuit with a resistance of 4.25 Ω. The current in the circuit is 0.755 A. The internal resistance of the battery is 0.635 Ω. What is the electromotive force of the battery?

Q11:

The graph shows the change in the current in a circuit with the terminal voltage of the battery that produces the current. What is the electromotive force of the battery?

What is the internal resistance of the battery?