2.4 Electromotive force and internal resistance

The cell has internal resistance, r, and electromotive force of 1.5 V.
What is the reading of voltmeter when the switch is closed?

• More than 3.0 V
• Less than 1.5 V
• More than 1.5 V
• 1.5 V

The circuit that can determine the electromotive force of the battery is

• A
• B
• C
• D

A battery has an e.m.f of 6.0 V. When it is connected to an external resistor, the potential different is 2.6 V and the current is 0.6 A. 
What is the value of the internal resistance?

• 3.4 Ω
• 4.3 Ω
• 4.4 Ω
• 5.7 Ω

What is the internal resistance of the battery in the circuit?

• 9.40 Ω
• 11.50 Ω
• 12.50 Ω
• 13.50 Ω

What is the internal resistance of the cell?

• 0.80 Ω
• 1.16 Ω
• 1.25 Ω
• - 1.25 Ω

One dry cell with e.m.f value of 2V and internal resistance 1Ω is connected to one resistor 4Ω.

What is the current in the circuit?

• 0.4A

• 0.5A

• 2.0A

• 2.5A

Determine:

(a) the e.m.f of the cell

*beza keupayaan(potential difference)

*Arus(current)

• 0.9

• 0.6

• 1.5

Which statement is FALSE about EMF?

• Energy supply by a source to transfer a unit charge from one terminal to another terminal

• No current flow in the circuit, voltmeter readings = e.m.f

• 
• There is current flow in the circuit. voltmeter readings = p.d across resistance

A battery of e.m.f. 12.0 V, with an internal resistance of 3.0 Ω, is connected in series with a 15.0 Ω resistor and a battery of e.m.f. 9.0 V, which has an internal resistance of 2.0 Ω. Calculate the p.d. of the 15Ω resistor.

• 15.75V

• 5.25V

• 15.25V

• 15.50V

What is internal resistance?

• the resistance inside the cell that increases with more current drawn from the cell

• the resistance inside the cell that decreases with more current drawn from the cell

• the resistance inside the cell that remains constant as the current drawn from the cell changes

• the resistance inside each component which increases as more resistances are added in series