Question

The resistance of ideal voltmeter is
1. Zero
2. Very less
3. Very high
4. Infinite

Answer 1

Correct Answer - Option 4 : Infinite

The correct answer is Infinite.

• A voltmeter is a device that is used to measure the potential difference between the two points in a circuit. 
• The resistance of an ideal voltmeter is infinite.
• In an ideal situation, where the voltmeter is able to measure the actual potential difference across two points, there should be no current passing through it, and hence its resistance should be infinite.

• Electric current is defined as the rate of flow of charge or electron, so its direction is the flow of positive charge.
  • SI unit of the current is Ampere(A) and it is a scalar quantity.
• Resistance is the opposition delivered by the conductor in which current flows through it.
• A device that is used to measure electric current in a circuit is called an ammeter.
  • The resistance of an ideal ammeter is always Zero and is always connected in the circuit in series.
• A galvanometer is a device that is used to detect and measure small electric currents in any circuit. 
• Now the interesting fact is:
  • We can convert a Galvanometer into an ammeter by connecting a shunt parallel to it.
  • A shunt is a small wire having very low resistance.
  • We can also convert a Galvanometer into a voltmeter by connecting a very high resistance in its series.