F5 Chapter 3.3 Electromotive force

Why must solar cells be arranged in series to form a solar panel?

• To reduce the current flow

• To reduce the internal resistance

• To produce high voltage

• To absorb more heat energy

The graph above shows the result in the experiment to determine the electromotive force and internal resistance of a battery. Which pair of the below is correct?

• Emf= 8V, r= 1Ჲ

• Emf= 10V, r=-1Ჲ

• Emf= 10V, r=1Ჲ

• Emf= 1V, r=10Ჲ

Which of the following can use to determine the electromotive force ?

• A

• B

• C

• D

Diagram below shows the Voltmeter reading of a circuit when the switch is open and closed. When the switch is closed, current of 0.4A flow through the bulb. What is the value of the internal resistance?

• 0.2Ჲ

• 0.4Ჲ

• 0.5Ჲ

• 0.8Ჲ

What is the reading of the voltmeter below?

• 5V

• 8V

• 10V

• 12V

Diagram below show a cell of emf 1.5V and internal resistance of 1 Ჲ. The switch is closed so the current can flow through the bulb. What is the reading on the voltmeter when the switch is closed?

• 0V

• 1.5V

• more than 1.5V

• less than 1.5V

Which of the following in the table below show the correct reading of v1 and v2?

• A

• B

• C

• D

When the switch is open V1=1.5V, when the switch is closed, V1=1.2V and A= 0.3A. What are the values of R and r?

• A

• B

• C

• D

What will happen if the dry cells are connected in parallel.

• Electromotive force increase, internal resistance increase

• Electromotive force increase, internal resistance decrease

• Electromotive force remain same, internal resistance increase

• Electromotive force remain same, internal resistance decrease

The advantage of connect the dry cells in series is

• the dry cell can last longer

• more energy supply

• can reduce the internal resistance

• can increase the internal resistance