1. The p-region has a greater concentration of __________ as compared to the n-region in a P-N junction.
a) holes
b) electrons
c) both holes & electrons
d) phonons
Explanation: Holes are the majority charge carriers in p-type material.
2. A p-type semiconductor material is doped with ____________ impurities whereas a n-type semiconductor material is doped with __________ impurities
a) acceptor, donor
b) acceptor, acceptor
c) donor, donor
d) donor, acceptor
Explanation: Donor impurities denote an electron to the n-type material making it a electron majority carrier & vice-versa.
3. In the p & n regions of the p-n junction the _________ & the ___________ are the majority charge carriers respectively.
a) holes, holes
b) electrons, electrons
c) holes, electrons
d) electrons, holes
Explanation: Holes are the majority charge carriers in p-type material & vice-versa.
4. The n-region has a greater concentration of _________ as compared to the p-region in a P-N junction diode.
a) holes
b) electrons
c) both holes & electrons
d) phonons
Explanation: Electrons are the majority charge carriers in n-type material
5. Which of the below mentioned statements is false regarding a p-n junction diode?
a) Diode are uncontrolled devices
b) Diodes are rectifying devices
c) Diodes are unidirectional devices
d) Diodes have three terminals
Explanation: Diode is a two terminal device, anode & cathode are the two terminals.
6. In the p & n regions of the p-n junction the _________ & the ___________ are the minority charge carriers respectively.
a) holes, holes
b) electrons, electrons
c) holes, electrons
d) electrons, holes
Explanation: Holes are the minority charge carriers in n-type material & vice-versa
7. Lets assume that the doping density in the p-region is 10-9 cm-3 & in the n-region is 10-17cm-3, as such the p-n junction so formed would be termed as a
a) p– n–
b) p+ n–
c) p– n+
d) p+ n+
Explanation: Doping density is greater in the p-region compared to the n-region
8. When a physical contact between a p-region & n-region is established which of the following is most likely to take place?
a) Electrons from N-region diffuse to P-region
b) Holes from P-region diffuse to N-region
c) Both of the above mentioned statements are true
d) Nothing will happen
Explanation: When p & n region come together diffusion takes places & a depletion region is established with opposite charges on both the sides of the junction.
9. Which of the following is true in case of an unbiased p-n junction diode?
a) Diffusion does not take place
b) Diffusion of electrons & holes goes on infinitely
c) There is zero electrical potential across the junctions
d) Charges establish an electric field across the junctions
Explanation: A potential difference is established across the junctions due to recombination of holes & electrons. This growing filed (barrier potential) stops the further diffusion.
10.Which of the following is true in case of a forward biased p-n junction diode?
a) The positive terminal of the battery sucks electrons from the p-region
b) The positive terminal of the battery injects electrons into the p-region
c) The negative terminal of the battery sucks electrons from the p-region
d) None of the above mentioned statements are true
Explanation: The diode is forward biased, positive is connected to p & vice-versa, as such batter provides EMF to drive electrons from n-region to p-region.