Which of the following statement is true for a p-n-p transistor when used in an amplifier circuit?

Options

A. Emitter is connected to negative terminal of a battery
B. Base current is always lower than emitter current
C. Collector is connected to positive terminal of battery
D. Collector current is always more than the emitter current

Answer

To determine which statement is true for a PNP transistor when used in an amplifier circuit, let's analyze the characteristics and functioning of a PNP transistor step by step.

### Step 1: Understand the Structure of a PNP Transistor
A PNP transistor consists of two p-type semiconductors and one n-type semiconductor. The arrangement is as follows:
- The **Emitter (E)** is made of p-type material.
- The **Base (B)** is made of n-type material.
- The **Collector (C)** is also made of p-type material.

### Step 2: Identify the Biasing of the Transistor
In an amplifier circuit:
- The **Emitter** is connected to the positive terminal of the battery (forward bias).
- The **Collector** is connected to the negative terminal of the battery (reverse bias).

### Step 3: Analyze the Current Relationships
In a PNP transistor:
- The **Emitter Current (I_E)** is the total current flowing out of the emitter.
- The **Base Current (I_B)** is the current flowing into the base.
- The **Collector Current (I_C)** is the current flowing out of the collector.

According to the transistor operation:
\[ I_E = I_B + I_C \]
This means the emitter current is the sum of the base current and the collector current.

### Step 4: Evaluate the Given Statements
1. **Emitter is connected to the negative terminal of a battery.**
- **False**: The emitter is connected to the positive terminal (forward bias).

2. **Base current is always lower than emitter current.**
- **True**: Since \( I_E = I_B + I_C \) and \( I_B \) is much smaller than \( I_E \), this statement is correct.

3. **Collector is connected to the positive terminal of the battery.**
- **False**: The collector is connected to the negative terminal (reverse bias).

4. **Collector current is always more than the emitter current.**
- **False**: This is incorrect because \( I_E = I_B + I_C \) implies that \( I_E \) is always greater than \( I_C \).

### Conclusion
The only true statement for a PNP transistor when used in an amplifier circuit is:
- **Base current is always lower than emitter current.**