Question

Which of the following are three-terminal devices?

(A) Zener diode
(B) Photodiode
(C) Bipolar Junction Transistor
(D) Field Effect Transistor
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (B) and (C) only.
• C. (C) and (D) only.
• D. (B) and (D) only.

Hint:

BJTs and FETs are three-terminal devices; diodes (Zener and photodiode) are two-terminal devices.

Answer 1

The Correct Option is C

Step 1: Three-Terminal Device Definition
- A three-terminal device possesses three connection points: input, output, and control.
- Zener and photodiodes are two-terminal devices.
- Bipolar Junction Transistors (BJTs) and Field Effect Transistors (FETs) are three-terminal devices. BJT terminals are the collector, base, and emitter; FET terminals are the source, gate, and drain.
Step 2: Summary
Therefore, BJTs (C) and FETs (D) are three-terminal devices.
Final Answer: \[ \boxed{\text{(C) and (D) only}} \]