A battery with an internal resistance of 0,5 Ω and an unknown emf (ε) is connected to
three resistors, a high resistance voltmeter and an ammeter of negligible resistance, as
shown in the circuit diagram below.
8.1 Define the term emf of a battery. (2)
The reading on the voltmeter DECREASES by 1,5 V when switch S is closed.
8.2 Give a reason why the voltmeter reading decreases. (2)
8.3 Calculate the following when switch S is closed:
8.3.1 Reading on the ammeter (3)
8.3.2 Total external resistance of the circuit (4)
8.3.3 Emf of the battery (3)
8.4 A learner makes the following statement:
The current through resistor R3 is larger than the current through resistor R2.
Is this statement CORRECT? Choose from YES or NO. Explain the answer. (3)
8.5 The 4 Ω resistor is now removed from the circuit.
How will this affect the emf of the battery? Choose from INCREASES,
DECREASES or REMAINS THE SAME.
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