Concepts Of Physics MCQ Edition [Volume 2]PhysicsSemiconductors and Semiconductor Devices
A semiconducting device is wired in a series circuit alongside a battery and a resistance. A current is observed to flow through the circuit. If the battery's polarity is reversed, the current drops to nearly zero. The device might be
Options
- Aa p -type semiconductor
- Ban n -type semiconductor
- Can intrinsic semiconductor
- Da p - n junction
Correct answer
D. a p - n junction
Step-by-step solution
A p - n junction diode allows current to flow when it is forward biased and offers very high resistance when it is reverse biased. When the battery's polarity is reversed, the p - n junction becomes reverse biased, causing the current to drop to nearly zero. In contrast, p -type, n -type, and intrinsic semiconductors conduct current equally in both directions regardless of the battery's polarity. Therefore, the device exhibiting this unidirectional conduction is a p - n junction.