Question

Which of the following instruments is used for detecting and measuring small electric currents?
A. galvanometer
B. flux meter
C. ammeter
D. voltmeter

Answer 1

Hint: The primary characteristic difference between an ammeter and a galvanometer is that ammeter is showing only the magnitude of the current. By the way, the galvanometer is showing both the direction and magnitude of the current passing through the circuit. This will help us in solving the question given.

Complete step by step solution:
A galvanometer is an electromechanical instrument that is used for detecting and indicating the presence of an electric current in an electric circuit. A galvanometer is working as an actuator by the production of rotary deflection using a pointer when an electric current is flowing through a coil in a fixed magnetic field. A galvanometer is basically a device or instrument for detecting even a small electrical current or a function of the current by making deflection in a moving coil. The deflection is a mechanical rotation happening due to the forces as a result of a current.

Hence the correct answer is option A.

Note: A flux meter is an instrument or an electric device that is used for the measurement of magnetic flux in stable magnets, the quality control of this, and sorting out the magnetic products. An ammeter is a measuring instrument which is used to calculate the amount of current in a circuit. Electric currents are measured usually in amperes (A). This is the reason for this name. This instrument is used to measure smaller currents in the millimeter micrometer range. A voltmeter is a device which is helpful for measuring the electric potential difference between any two points in an electric circuit.