Question

Which of the following statement(s) is/are true?

• A. In intrinsic semiconductors, the number of electrons is equal to the number of holes at any temperature
• B. An intrinsic semiconductor changes to an n-type semiconductor upon addition of a trivalent element
• C. The shape of the I-V characteristics of a p-n diode is a straight line
• D. In the reverse bias condition, the current in a p-n diode is due to the minority carriers

Hint:

In a p-n junction, current under reverse bias is due to the minority carriers, which is opposite to the behavior under forward bias.

Answer 1

The Correct Option is A, D

Step 1: Understanding semiconductor behavior.
In intrinsic semiconductors, the number of free electrons is equal to the number of holes. An intrinsic semiconductor becomes an n-type semiconductor when a trivalent element is added, creating additional free electrons. The I-V characteristics of a p-n diode are non-linear, not straight. In reverse bias, the current in a p-n diode is carried by the minority carriers.
Step 2: Analyzing the options.
(A) In intrinsic semiconductors, the number of electrons is equal to the number of holes at any temperature: True — This is a characteristic of intrinsic semiconductors.
(B) An intrinsic semiconductor changes to an n-type semiconductor upon addition of a trivalent element: Incorrect — A trivalent element (which creates holes) would make the semiconductor p-type, not n-type.
(C) The shape of the I-V characteristics of a p-n diode is a straight line: Incorrect — The I-V characteristics of a p-n diode are non-linear and exponential, not linear.
(D) In the reverse bias condition, the current in a p-n diode is due to the minority carriers: Correct — In reverse bias, the current is due to the minority carriers in a p-n junction.
Step 3: Conclusion.
The correct answer is (D) In the reverse bias condition, the current in a p-n diode is due to the minority carriers.