21. In a semiconductor, current conduction is due to A. Only holes B. Only free electrons C. Holes and free electrons D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
22. As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor ___________ A. Remains the same B. Increases C. Decreases D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
23. When a pentavalent impurity is added to a pure semiconductor, it becomes A. An insulator B. An intrinsic semiconductor C. p-type semiconductor D. n-type semiconductor Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
24. The barrier voltage at a pn junction for germanium is about A. 5.0 V B. 3.0 V C. Zero D. 0.3 V Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
25. In the depletion region of a pn junction, there is a shortage of A. Acceptor ions B. Holes and electrons C. Donor ions D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
26. A trivalent impurity has valence electrons A. 4 B. 5 C. 6 D. 3 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
27. The random motion of holes and free electrons due to thermal agitation is called ___________ A. Diffusion B. Pressure C. Ionisation D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
28. The leakage current across a pn junction is due to ___________ A. Minority carriers B. Majority carriers C. Junction capacitance D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
29. When a pure semiconductor is heated, its resistance ___________ A. Goes up B. Goes down C. Remains the same D. Can?t say Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
30. A reverse bias pn junction has ___________ A. Very narrow depletion layer B. Almost no current C. Very low resistance D. Large current flow Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board