Question

In an electric circuit, current starts from the-
A. Positive terminal
B. Either of the two terminals.
C. Negative terminal.
D Depends upon the circuit

Answer 1

The current in an electrical circuit or wire flows due to the movement of charge. The charge is nothing but electrons. If a body has more excessive electrons then the body is negatively charged and if a body has shortage or absence of electrons then the body is positively charged. The direction of current is conventionally taken to be opposite to flow of electrons.

Complete step by step answer:
The current in a circuit is produced due to flow of electrons and is defined as the rate of charge flow. In a wire or conductor when no battery is connected the electrons inside the wire flow in random directions so the average velocity of the electrons is taken to be zero in absence of battery or external field. When a battery is connected the electrons will flow from the negative terminal of the battery to the positive terminal. So electrons will start moving from the negative terminal to the positive terminal.
But the direction of the current is conventionally taken to be opposite to the direction of the charge flow. As the motion of electrons ends at the positive terminal of the battery so the electric current starts from the positive terminal of the battery.
So the option A is correct.

Note:
Electrons or charge flow from higher potential of charge to lower potential of charge to maintain balance in the number of electrons. This flow of charge or electrons produces electric current.
Also note that the electric current has both magnitude and direction but it is not a vector quantity because the electric current does not obey vector law of addition and can be added algebraically.
Unit of electric current is Ampere (A). In SI units the electric current is one of the seven fundamental quantities.