Question

What is meant by electric current? Name and define S.I unit. In a conductor electrons are flowing from B to A. What is the direction of conventional current? Give justification for your answer.

Answer 1

Hint: Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. Current flows from relatively positive points to relatively negative points.

Formula used:As required here we need ohm’s law:
$I = Q/t$
Here, $I$ is the current,
$Q$ is the amount of charge flowing in the carrier
$t$ is the time period.

Complete step-by-step answer
The amount of charge $Q$ flowing through a particular area of cross section in unit time $t$ is called electric current.
Electric current constitutes of any movement of electric charge carriers, such as subatomic charged particles (e.g., electrons having negative charge, protons having positive charge), ions (atoms that have lost or gained one or more electrons), or holes (electron deficiencies that may be thought of as positive particles).Also, Ohm’s law can be used to determine current.
The SI unit of electric current is ampere. One ampere of current is the current which flows when one coulomb of electric charge flows through a particular area of cross-section of the conductor in one second.
The direction of conventional current is A to B, since current flows opposite to the direction of flow of electrons. In a metal, flow of electrons carrying negative charge constitutes the current. Direction of flow of electrons gives the direction of electric current by convention, the direction of flow of positive charge is taken as the direction of conventional current.

Additional Information
Ohm's law is the fundamental law in the field of electricity. It was discovered by George Ohm, and named after him. Ohm's law provides the relationship between current, voltage, and resistance. It states that the voltage across any resistance is equal to current times the resistance.

Note
Electric current, any movement of electric charge carriers, such as subatomic charged particles (e.g., electrons having negative charge, protons having positive charge), ions (atoms that have lost or gained one or more electrons), or holes (electron deficiencies that may be thought of as positive particles).