A charged particle moving with a uniform velocity `vecv` enters a region where uniform electric and magnetic fields `vecE` and `vecB` are present. It passes through the region without any change in its velocity. What can we conclude about the (i) relative direction of `vecE`, `vecV` and `vecB`? (ii) magnetic of `vecE` and `vecB`?
or
Find the condition under which the charged particle moving with different speeds in the presence of electric and magnetic field vectors can be used to select charged particles of a particular speeds.

Explanation

To solve the problem step by step, let's break down the information given and derive the conclusions for both parts of the question.

### Step-by-Step Solution

1. **Understanding the Problem:**
A charged particle with charge \( Q \) and mass \( m \) is moving with a uniform velocity \( \vec{v} \) and enters a region with uniform electric field \( \vec{E} \) and magnetic field \( \vec{B} \). It passes through this region without any change in its velocity, meaning there is no net force acting on it.

2. **Forces Acting on the Charged Particle:**
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