Postby TGTS0907129» Potential change when voltmeter connected points

Describe the change in potential difference when a voltmeter is connected between points


When a voltmeter is connected between points whose potential difference is to be measured, the potential difference is changed by the presence of voltmeter. When the voltmeter is placed in parallel with a portion of the circuit, the resistance is reduced; hence the potential difference and the total current are increased. The voltmeter introduces two errors: changing the current in the circuit and reducing the potential difference that is to be measured. In order that these errors be small, it is essential that the resistance of the voltmeter be very large in comparison with the resistance across which it is connected. This will ensure also that the current in the voltmeter be small in comparison with that in the main circuit.

By TGTT06081269 on 9/18/2015 3:47:00 AM
TGTS0907129 on 9/18/2015 3:44:50 AM

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