Understanding EMF and Internal Resistance

Which of the following is NOT a method to measure EMF and internal resistance mentioned in the video?

• Simultaneous Equations

• Voltage Divider Method

• Linear Graph Method

• Open/Closed Circuit Method

In an open circuit, what does the voltmeter reading represent?

• The terminal potential difference

• The internal resistance

• The EMF of the cell

• The current in the circuit

What happens to the current flow in a closed circuit?

• No current flows

• Current flows through the voltmeter only

• Current flows through the entire circuit

• Current is blocked by the internal resistance

In the first example problem, what is the EMF of the cell when the switch is off?

• 3.0 V

• 2.5 V

• 5.0 V

• 4.5 V

How is the internal resistance calculated in the first example problem?

• By using the formula E = V + IR

• By subtracting the terminal potential difference from the EMF

• By measuring the current directly

• By using the formula V = IR

In the second example problem, what is the load resistance value?

• 5 ohms

• 9 ohms

• 1 ohm

• 2 ohms

What is the first step in finding the internal resistance in the second example problem?

• Measure the terminal potential difference

• Find the current using V = IR

• Use the formula E = V + IR directly

• Calculate the EMF

In the final example problem, what is the terminal potential difference when the switch is closed?

• 4.5 V

• 3.0 V

• 2.5 V

• 5.0 V

What is the internal resistance calculated in the final example problem?

• 2 ohms

• 1.5 ohms

• 0.5 ohm

• 1 ohm

What is the significance of the EMF in an open circuit?

• It is always less than the terminal potential difference

• It is the maximum potential difference the cell can provide

• It is equal to the terminal potential difference

• It is irrelevant in an open circuit