Question

The current drawn by the non-ideal voltmeter in an electric circuit is:
A. Small
B. Large
C. Infinity
D. Zero

Answer 1

Hint: Voltmeter is a device that is used to determine the potential difference between two points in an electric circuit in which current is flowing. It is always connected in parallel to the load to get the accurate value of potential difference

Complete step-by-step answer:
Voltmeter is always connected in parallel to the load in the circuit. Unlike ammeter, which is connected in series to the load, so that all of the current can flow through the ammeter and can be accurately measured. In case of voltmeters, only a small current is required to measure the voltage, hence the resistance should be large enough.
This is due to the fact that if two resistors are connected in parallel and current is flown then more current will flow through the resistor having lesser resistance. Suppose if the resistance of one of them becomes zero, then all of the current will flow through that resistor or wire (as it will simply be a wire). This is the concept of a short circuit.
Hence, we can say, if the resistance of voltmeter is lesser, maximum current will flow through it only and that will affect the current in the load there by dropping the potential difference across the load. Hence in order to draw smaller current, higher resistance is used. Option B. is correct.

Note: In the question, it is given that the volt-meter is non-ideal. But for the case of ideal voltmeter, the resistance of voltmeter should be infinite. In case of an ammeter, the resistance should be small, otherwise due to its higher resistance, the potential difference across its ends will be large hence by dropping voltage across the load.