PHYS 1112 Module 7.2

Activity 3: Electromotive Force (emf) and Terminal Voltage

Practice 7.2.1

For the circuit shown where r is an internal resistance and R is an external resistor, which potential difference corresponds to the terminal voltage of the battery?
Check your answer: C. between points K and M
Practice 7.2.2

A battery has emf = 12.0 V and internal resistance  = 3.00 Ω. A voltmeter is connected to the terminals of the battery; the battery is not connected to any other external circuit elements.

What is the reading of the voltmeter?
Check your answer: B. 12 V
Practice 7.2.3

A battery has emf = 12.0 V and internal resistance r = 3.00 Ω. A 21.0-Ω resistor is connected to the terminals of the battery.

What is the current through the battery?
Check your answer: B. 0.50 A
Practice 7.2.4

A battery has emf = 12.0 V and internal resistance r = 3.00 Ω. A 21.0-Ω resistor is connected to the terminals of the battery.

What is the current through the 21.0-Ω resistor?
Check your answer: B. 0.50 A
Practice 7.2.5

A battery has emf = 12.0 V and internal resistance r = 3.00 Ω. A 21.0-Ω resistor is connected to the terminals of the battery.

What is the potential difference across the 21.0-Ω resistor?
Check your answer: B. 10.5 V
Practice 7.2.6

A battery has emf = 12.0 V and internal resistance r = 3.00 Ω. A 21.0-Ω resistor is connected to the terminals of the battery.

What is the terminal voltage of the battery connected to the 21.0-Ω resistor?
Check your answer: B. 10.5 V