Select the correct statement(s).

Options

A. The conductance through electron is called `p`-type conducation.
B. The conductance through positive holes is called `p`-type conduction.
C. The conductance through electrons is called `n`-type conduction.
D. The band gap in germanimum is small.

Answer

To solve the question of selecting the correct statements regarding semiconductor conduction, we will analyze each option step-by-step.

### Step-by-Step Solution:

1. **Analyze Option 1**:
- The statement is: "The conductance through electrons is called p-type conduction."
- **Explanation**: This statement is incorrect. The conductance through electrons is known as n-type conduction, not p-type. In n-type semiconductors, electrons are the majority charge carriers.

2. **Analyze Option 2**:
- The statement is: "The conductance through positive holes is called p-type conduction."
- **Explanation**: This statement is correct. In p-type semiconductors, holes (which are the absence of electrons and act as positive charge carriers) are the majority carriers.

3. **Analyze Option 3**:
- The statement is: "The conductance through electrons is called n-type conduction."
- **Explanation**: This statement is also correct. As previously mentioned, n-type semiconductors have electrons as the majority charge carriers, which is the definition of n-type conduction.

4. **Analyze Option 4**:
- The statement is: "The band gap in germanium is small."
- **Explanation**: This statement is correct. Germanium is a semiconductor with a small band gap, which allows electrons to jump from the valence band to the conduction band with relatively low energy, making it effective for conduction.

### Conclusion:
- The correct statements are:
- Option 2: "The conductance through positive holes is called p-type conduction."
- Option 3: "The conductance through electrons is called n-type conduction."
- Option 4: "The band gap in germanium is small."

Thus, the correct options are **2, 3, and 4**.