Question

The resistance of an ideal ammeter is…
A. Zero
B. Low
C. High
D. Infinite

Answer 1

First of all we should know about the ammeter and resistance. The instrument that is used for measuring either direct or alternating electric current, in amperes is known as ammeter. Resistance is the opposition in the flow of current. It prevents the current from flowing throughout the conductor.

Complete answer:
An ammeter can measure a wide range of current values because at high values only a small portion of the current is directed through the meter mechanism; a shunt in parallel with the meter carries the major portion.The principle of ammeter is that the resistance and inductive reactance must be very low.

Ammeters consist of very low resistance as the voltage drop across the ammeter must be low. The ammeter must be connected in series in order to fulfill the above conditions.The resistance of an ideal ammeter is zero. A “clamp-on” ammeter (an electrical meter with integral AC current clamp is known as a clamp meter, clamp-on ammeter) which measures the current with the help of a wire.

It measures the strength of the magnetic field around it, rather than by becoming part of the circuit, making it an ideal ammeter.The process of converting an ammeter into an ideal ammeter is very simple. In this process we have to only connect shunt in parallel with the ammeter. The shunt is nothing, just a resistor with a very low resistance.

Hence, option A is correct.

Note: An ammeter is a device which is mainly connected in series with the circuit in order to measure the current. The ideal ammeter will have zero resistance so that it will not disturb the circuit.The principle of ammeter is that the resistance and inductive reactance must be very low. Ammeter has a very low impedance as the voltage drop across the ammeter should be low.