Question

In the given statements, find the incorrect statement and correct the mistakes.

A magnetic field is a quantity that has magnitude only.

Answer 1

Magnetic Field

1. The magnetic field is defined as the force per unit charge moving with unit velocity perpendicular to the magnetic field.
2. The magnetic field can exert force on a moving charge or a current-carrying conductor.
3. A magnetic field can be measured by measuring these magnetic forces.
4. The force on a charge $q$ moving with velocity $\overrightarrow{v}$ in a magnetic field $\overrightarrow{B}$ is $\overrightarrow{F_m}=q\left(\overrightarrow{v}\times \overrightarrow{B}\right)$.
5. If, in addition, there is an electric field $\overrightarrow{E}$ then the total electromagnetic force on the charge will be $\overrightarrow{F}=q\left[\overrightarrow{E}+\overrightarrow{v}\times \overrightarrow{B}\right]$.
6. Therefore, a magnetic field $\overrightarrow{B}$ is a vector quantity.

Hence, a magnetic field is a vector quantity that has both magnitude and direction.