Question

A strong magnetic field is applied on a stationary electron. Then the electron

• A. Moves in the direction of the field
• B. Moves in an opposite direction of the field
• C. Remains stationary
• D. Starts spinning

Answer 1

The Correct Option is C

Step 1: Consider the force on a stationary electron in a magnetic field.

The Lorentz force on a charge $q$ moving with velocity $\vec{v}$ in a magnetic field $\vec{B}$ is $\vec{F} = q(\vec{v} \times \vec{B})$.

Step 2: Apply the condition of a stationary electron.

For a stationary electron, the velocity $\vec{v} = 0$.

Therefore, the magnetic force $\vec{F} = q(0 \times \vec{B}) = 0$.

Step 3: Determine the motion of the electron.

Since the net magnetic force on a stationary electron is zero (and assuming no other forces are considered in this simplified scenario), the electron will remain stationary.

The correct answer is (C) Remains stationary.

Answer 2

A magnetic field exerts a force on a moving charge. The force is given by $\vec{F} = q(\vec{v} \times \vec{B})$, where $q$ is the charge, $\vec{v}$ is the velocity, and $\vec{B}$ is the magnetic field. 

Since the electron is stationary ($\vec{v} = 0$), the magnetic force on it is zero.

A stationary electron in a magnetic field does not experience a force unless it is in motion. The magnetic force on a charged particle is given by the Lorentz force law, which states that the force depends on the velocity of the particle. Since the electron is stationary, its velocity is zero, and thus no magnetic force acts on it, so it remains stationary.

The correct answer is (C) Remains stationary.