NEETPhysicsSemiconductors
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The electric field across the junction of a Zener diode is very high (of the order of 5 10^6 V/m ) even for a small reverse bias voltage of about 5 V . Reason (R): Both p and n regions of a Zener diode are lightly doped, which results in a wide depletion region. In the light of the above statements
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
C. Assertion (A) is true but Reason (R) is false
Step-by-step solution
Assertion (A) is true. In a Zener diode, a small reverse bias voltage (e.g., 5 V ) across a very thin depletion region (e.g., Reason (R) is false. A Zener diode is heavily doped on both the p and n sides, which is exactly what causes the depletion region to be very thin, not wide. Answer: Assertion (A) is true but Reason (R) is false