Chapter 36, Problem 24A

“An electron always experiences a force in an electric field, but not always in a magnetic field,” Defend this statement.

To determine

To Explain: The electron always experiences a force in the electric field, but not always in a magnetic field.

Explanation of Solution

Introduction:

Force experienced by an electron in an electric field is given by: $F=Eq$

Force experienced by an electron in a magnetic field is given by: $F=qvB\sin \theta$

In case of an electric field force is the product of electric field and the charge on the electron. While in case of magnetic field, the force depends upon an additional factor of velocity. When the electron is stationary, then it will experience a force in an electric field but in case of magnetic field there will be no force, according to the formula of magnetic force. When the electron is moving, then it will experience a force in an electric field as well as magnetic field.

Hence, an electron always experiences a force in the electric field but not always in the magnetic field.

Conclusion:

The electron experiences the force in the electric field but not in the magnetic field because in case of magnetic field only the moving charge can experience a force.