Question

Consider the following statements:
(A) Built-in potential across a diode reduces with increase in temperature.
(B) Electron concentration of n-type semiconductor equals intrinsic concentration at Curie temperature.
(C) Drain current of MOSFET is a positive temperature coefficient (PTC).
(D) Collector current of BJT has a PTC.
Choose the correct statements:

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

Hint:

Remember: MOSFET is safer in parallel due to negative coefficient, BJTs are not.

Answer 1

The Correct Option is B

- (A) True: $V_{bi}$ decreases with temperature.
- (B) True: At high temperature, electron concentration approaches intrinsic concentration.
- (C) False: MOSFET has a negative temperature coefficient (NTC), not PTC.
- (D) True: The collector current of BJT increases with temperature (PTC).
Thus, the correct options are (A), (B), and (C).
Final Answer: \[ \boxed{(2) \, (A), (B) \, \text{and} \, (C) \, \text{only}} \]