Question

Is electric current a scalar or vector quantity? State the standard unit of electric current.

Answer 1

Hint:As we know that, A scalar quantity is defined as the physical quantity that has only magnitude. For example- Mass, electric current, volume, speed, area, temperature, density. Whereas A vector quantity is defined as the physical quantity that has both magnitude as well as direction. For example - Force, weight, displacement, momentum, acceleration, angular velocity

Complete answer:
Electric current is a scalar quantity. Any physical quantity is defined as a vector quantity when the quantity has both magnitude and direction but there are some other factors which show that electric current is a scalar quantity . When two currents meet at a point the resultant current will be an algebraic sum. In scalar quantities, normal rules of algebra are applicable while in vector quantities different sets of rules are applicable. That’s why we can say that electric current is a scalar quantity.

The standard unit of electric current is Ampere.

Note: Current is a vector because it has a magnitude and a direction. But the thing is a vector always obeys the law of addition of vectors. Since current doesn't obey it and it follows algebraic addition, currents are scalar. Also, current is written as the dot product of the current density vector and the area vector. Cgs unit is biot.