Question

Which of the following instruments is used to measure the electric current?
A. Voltmeter
B. Ammeter
C. Barometer
D. Galvanometer

Answer 1

Hint: An ammeter can calculate a vast range of current values, but at high values, only a small portion of the current is guided by the meter mechanism; a shunt parallel to the meter carries the main portion of the current.

Complete step-by-step solution:
To solve this question, first, we have to know about electric current. The electrical current is the electrical charge flow in the circuit. Specifically, electrical current is the rate of charge flow past the point in the electrical circuit. The charge can be positively charged or negatively charged electrons carriers. The electron movement is from negative to positive terminals. Electrons are charged negatively and are thus drawn to the positive terminal because they do not attract charges.
Now, let us find the solution from the given options -
A voltmeter is an instrument used to calculate the electrical potential difference between two points in an electrical circuit. Analog voltmeters shift the pointer over a scale in relation to the voltage of a circuit whereas; digital voltmeters show the voltage by means of an analog-to-digital converter.
The ammeter is a measurement device that is used to calculate the current in a circuit. Electrical currents are expressed in amperes, hence the name.
The barometer is a scientific instrument used to determine air pressure in a given area. Most
measures of air pressure are used in surface weather forecasting to help locate pressure systems, surface troughs, and frontal boundaries.
The galvanometer is an electromechanical device used to measure and indicate electrical current.
The galvanometer serves as an actuator, creating a rotary deflection in response to the electrical current flowing through the coil in a static magnetic field.
Thus, the right answer is option B. i.e., Ammeter.

Note: The galvanometer can be converted into an ammeter by linking the resistance in the electrical circuit in parallel. It can be used as a voltmeter when the resistance is attached in series to it. An ammeter is used to calculate the present magnitude. This is also called an ampere meter since the ampere is the present level.