An electron beam with equivalent electric current I enters a region of crossed electric field and magnetic field B. Both the fields are uniform. It is found that the electron beam goes undeviated through the region of fields. After passing the field region, electrons hit a grounded target. How much force is exerted by the electron beam on urget? Assumem is the mass of electron and e its charge.

Explanation

To solve the problem step by step, we will analyze the situation involving the electron beam, the forces acting on it, and the resulting force exerted on the grounded target.

### Step-by-Step Solution:

1. **Understanding the Electron Beam**:
- We have an electron beam that carries an equivalent electric current \( I \). This beam enters a region where there are crossed electric field \( E \) and magnetic field \( B \).

2. **Condition for Undeviated Motion**:
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