A strong magnetic field is applied on a stationary electron, then

Options

A. moves in the direction of the field.
B. remained stationary.
C. moves perpendicular to the direction of the field.
D. moves opposite to the direction of the field.

Explanation

To solve the question, we need to analyze the situation where a strong magnetic field is applied to a stationary electron. Here’s the step-by-step solution:

### Step 1: Understand the scenario
We have a stationary electron, which means its initial velocity (V) is zero. The magnetic field (B) is applied in a certain direction.

**Hint:** Remember that the motion of a charged particle in a magnetic field depends on its velocity.

### Step 2: Recall the formula for magnetic force
The force (F) experienced by a charged particle in a magnetic field is given by the formula:
\[ F = Q (\vec{V} \times \vec{B}) \]
where:
- \( Q \) is the charge of the particle,
- \( \vec{V} \) is the velocity vector of the particle,
- \( \vec{B} \) is the magnetic field vector.

**Hint:** The cross product indicates that the force is dependent on both the velocity and the magnetic field direction.

### Step 3: Substitute the values
Since the electron is stationary, its velocity \( \vec{V} = 0 \). Therefore, we can substitute this into the formula:
\[ F = Q (0 \times \vec{B}) \]

**Hint:** Think about what happens to the force when the velocity is zero.

### Step 4: Calculate the force
From the substitution, we find:
\[ F = Q \cdot 0 = 0 \]

This means that the force acting on the electron is zero.

**Hint:** A zero force means there is no change in motion.

### Step 5: Conclusion
Since the force is zero, the stationary electron will remain stationary even when a magnetic field is applied. Therefore, the correct answer to the question is that the electron will remain stationary.

**Final Answer:** The electron remains stationary (Option B).