Assertion–Reason: The phenomenon of differential mobility is called the transferred electron effect. Gallium Arsenide (GaAs) exhibits this effect. Evaluate correctness of Assertion (A) and Reason (R).
-
ABoth A and R are correct and R is correct explanation of A
-
BBoth A and R are correct but R is not the correct explanation of A
-
CA is correct but R is wrong
-
DA is wrong but R is correct
-
EBoth A and R are wrong
Answer
Correct Answer: Both A and R are correct and R is correct explanation of A
Explanation
Introduction / Context:This question explores semiconductor physics concepts behind the Gunn effect and transferred electron devices. Understanding differential mobility is important in high-frequency microwave device design.
Given Data / Assumptions:
- Assertion: Differential mobility phenomenon is termed transferred electron effect.
- Reason: GaAs exhibits transferred electron effect.
Concept / Approach:Transferred electron effect occurs in materials like GaAs where electrons move from a high-mobility valley to a low-mobility valley under strong electric fields. This leads to negative differential resistance, enabling oscillators.
Step-by-Step Solution:
Assertion is correct: definition of transferred electron effect.Reason is correct: GaAs is the classical material exhibiting this effect (basis of Gunn diodes).Reason also explains Assertion correctly, as GaAs is the experimental evidence of the phenomenon.Verification / Alternative check:Microwave engineering textbooks confirm GaAs shows Gunn oscillations due to transferred electron effect.
Why Other Options Are Wrong:
Any option denying either A or R contradicts semiconductor physics facts.Common Pitfalls:
Confusing transferred electron effect with avalanche or tunneling effects.Final Answer:
Both A and R are correct and R is correct explanation of A