6 April 2020

Why voltmeter has high resistance?

Voltmeters supposed to have infinite/very high resistance to avoid loading effect. The voltmeter is constructed with very high internal resistance the reason of that it measures the potential difference between the two points of the circuit. At that time, the voltmeter does not change the current of the measuring device.

If we consider the resistance of the voltmeter won't be high, it would draw some current and the other resistors connected in parallel with it will not get enough current through them.

If the voltmeter considers being to be low resistance the current passes through it, and the voltmeter gives the incorrect or wrong result. The high resistance of the voltmeter does not allow the current to pass through it and thus that time the correct reading is obtained.