Question 1
A battery is connected to a 10 Ω resistor and a switch in series. A voltmeter is connected across the battery. When the switch is open (off) the voltmeter reads 1.45 V. When the switch is closed the reading is 1.26 V.
What is the internal resistance of the battery?
0.66 Ω
0.76 Ω
1.3 Ω
1.5 Ω
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Question 2
In the circuit shown, the cell has an emf of 12 V and an internal resistance which is not negligible.
When the resistance of the variable resistor is 10 Ω the voltmeter reads 10 V and the ammeter reads 1.0 A.
The resistance of the variable resistor is changed to 5 Ω.
What is the new reading on the ammeter?
1.4 A
1.7 A
2.0 A
2.4 A
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Question 3
Two identical batteries each of emf 1.5 V and internal resistance 1.6 Ω are connected in parallel. A 2.4 Ω resistor is connected in parallel with this combination.
What is the current in the 2.4 Ω resistor?
0.38 A
0.47 A
0.75 A
0.94 A
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Question 4
In the circuit, the reading of the voltmeter is V.
When the switch is closed the reading becomes .
What is the internal resistance of the cell?
0.33 Ω
0.67 Ω
4.0 Ω
6.0 Ω
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Question 5
The diagram below shows a cell with an internal resistance connected to an external resistor.
Which of the following will increase the terminal p.d?
1 - Increasing the e.m.f. of the cell.
2 - Increasing the value of the external resistance.
3 - Increasing the value of the internal resistance.
1, 2 and 3
only 1 and 2
only 2 and 3
only 1
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Question 6
A battery of e.m.f. of 8.0 V and internal resistance 2.5 Ω is connected to an external resistor. The current in the resistor is 350 mA.
What is the power dissipated in the external resistor?
1.9 W
2.5 W
2.8 W
3.1 W
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Question 7
A source of e.m.f. of 9.0 mV has an internal resistance of 6.0 Ω.
It is connected across a galvanometer of resistance 30 Ω.
What will be the current in the galvanometer?
250 µA
300 µA
1.5 mA
2.5 mA
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Question 8
The battery of a car has an internal resistance of 0.10 Ω and an electromotive force of 12 V. When the battery is connected to the starter motor, the potential difference across the battery terminals is 7.0 V.
What is the current supplied to the starter motor?
50 A
70 A
120 A
190 A
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