To identify whether the transistor is working or not, using multimeter, which statement serves the purpose?

Options

A. The common lead of multimeter is connected to base and other lead to first emitter and then to collector, only 1st connection shows the continuity
B. The common lead multimeter is connected to base and other lead to first emitter and then to collector, both the connection shows the continuity
C. The common lead of multimeter is connected to base and other lead to first emitter and then to collector, none of the connections show the continuity
D. All of the above

Answer

To determine whether a transistor is functioning properly using a multimeter, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Type of Transistor**:
- Determine whether the transistor is a PNP or NPN type. This is crucial because the testing procedure differs slightly for each type.

2. **Set Up the Multimeter**:
- Set the multimeter to the diode test mode. This mode allows you to check for continuity and the forward bias condition of the transistor.

3. **Connect the Multimeter Leads**:
- For a **PNP transistor**:
- Connect the common lead (usually black) of the multimeter to the base terminal of the transistor.
- Connect the positive lead (usually red) to the emitter terminal.
- Connect the positive lead (red) to the collector terminal.
- For an **NPN transistor**:
- Connect the common lead (black) to the base terminal.
- Connect the positive lead (red) to the collector terminal.
- Connect the positive lead (red) to the emitter terminal.

4. **Check for Continuity**:
- For a PNP transistor:
- If both connections (base to emitter and base to collector) show continuity (a beep or a reading on the multimeter), the transistor is functioning properly.
- If only one connection shows continuity, the transistor may be faulty.
- If neither connection shows continuity, the transistor is faulty.
- For an NPN transistor:
- The same logic applies. If both connections show continuity, the transistor is good; if one or neither shows continuity, it is faulty.

5. **Interpret the Results**:
- Based on the continuity checks, you can conclude whether the transistor is working properly or if it is faulty.

### Conclusion:
- The correct statements regarding the testing of the transistor using a multimeter are:
- If both connections show continuity, the transistor is in good condition.
- If only one or neither connection shows continuity, the transistor is faulty.