A changed particle mvoes along a circle under the action of possible constant electric and magnetic fields. Possible case is

Options

A. E=0, B=0
B. E=0 B≠
0
C. E≠0 , B=0
D. E≠
0 , B≠
0

Explanation

To solve the problem of a charged particle moving along a circular path under the influence of electric and magnetic fields, we need to analyze the forces acting on the particle and their implications for circular motion.

### Step-by-Step Solution:

1. **Understanding the Forces**:
- A charged particle (let's denote it as \( Q \)) experiences forces due to electric and magnetic fields. The electric force \( \vec{F_E} \) is given by \( \vec{F_E} = Q \vec{E} \) and the magnetic force \( \vec{F_B} \) is given by \( \vec{F_B} = Q \vec{v} \times \vec{B} \).

2. **Direction of Forces**:
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