An n type semiconductor of conductivity 6 `Ω^(-1) cm^(-1)` is produced when donor atoms are added to an intrinsic germanisum crystal ignoring the contributio of holes to conductivity and taking mobility of electron in n type Ge equal to 3500 `cm^(2)` /Vs determine the number density of donor atoms used for doping

Explanation

To determine the number density of donor atoms used for doping in an n-type semiconductor, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Data:**
- Conductivity (\( \sigma \)) = 6 \( \Omega^{-1} \, \text{cm}^{-1} \)
- Mobility of electrons (\( \mu_e \)) = 3500 \( \text{cm}^2/\text{V}\cdot\text{s} \)
- Charge of an electron (\( e \)) = \( 1.6 \times 10^{-19} \, \text{C} \)
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