A battery is to be used with a resistor in the school laboratory

PHYSICS · Multi-part · GCSE · Physics · Electricity · Electricity

Problem

6\,\text{V}

battery is to be used with a

20\,\Omega

resistor in the school laboratory. Two ammeters are available: Ammeter–1: range

0\text{–}200\,\text{mA}

Ammeter–2: range

0\text{–}1\,\text{A}

The internal resistance of Ammeter–2 is

0.2\,\Omega

, while that of Ammeter–1 can be taken as negligible. (i) Calculate the current that should ideally flow through the

20\,\Omega

resistor when connected to the

6\,\text{V}

battery. (ii) Decide which ammeter (Ammeter–1 or Ammeter–2) should be chosen to measure this current accurately. Justify your choice with suitable reasoning. (iii) If Ammeter–2 is used in series with the resistor, determine the current that will actually flow in the circuit, taking its internal resistance into account. (iv) Calculate the percentage error in the measured current due to the internal resistance of Ammeter–2.

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