in spite of having  magnitude as well as direction , why the electric  current  is  a scalar quantity ?
pls explain  briefly .

Asked by ppratim02 | 19th Aug, 2016, 07:47: PM

Expert Answer:

Electric current (I) through a given area of a conductor is the rate of flow of electric charge through the area.Conventionally the direction of electric current is taken along the direction of motion of positive charges.

For a quantity to be a vector: 1) it has to have magnitude and direction

                                               2) it has to obey the laws of vector addition .

Current satisfies the first but fails the second therefore it is a scalar quantity.

i.e if two currents meet at a junction, the total current of the resultant will be the algebraic sum of the two current and not the vector sum.So even though current has direction, it is a scalar quantity.

Answered by Yashvanti Jain | 22nd Aug, 2016, 11:56: AM