Question

a voltmeter of resistance 400 ohm is used to measure the potential difference accross 100 ohm resistor in the curciut shown in the figure.what will be the reading of voltmeter.

Answer 1

The voltmeter will display the voltage across the 100 ohm resister which will be fairly accurate. However depending upon the placement of the resister and the other components of the circuit there may be loading effect on the voltmeter which will lead to deviation in the result. To reduce this loading effect the internal impedance of a voltmeter is kept very high.

Therefore in this case as the internal impedance of the voltmeter is fairly low there can be higher extent of loading effect which may give an inaccurate result.

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