MCQ on Semiconductor | Updated Pdf
Multiple Choice Questions on Semiconductors pdf
Hello Students, how are you all hope you all will be good, in this Page we have shared with you more than 50 Important MCQ on Semiconductor which is helpful for verious entrance exams preparation. This Multiple Choice Questions on Semiconductors pdf will help you enhance your performance in entrance exams like NEET and JEE. Before starting Semiconductor MCQs know the What js semiconductor.
On the basis of band theory of solids, the substances are divided into three groups
(i) conductors
(ii) semi conductors
(iii) Insulators
In an atom, the upper most empty energy band is called the Conduction band. The lowest completely filled energy band is called the Valence band. The forbidden band lies between the conduction band and the valence band. The electrons are forbidden to occupy it. The difference in the energy levels of conduction and energy bands is called the forbidden energy gap. For conductors it is practically zero. For insulators it is very large 5 to 15 eV). For semiconductors it is about 1 eV.
Semiconductors, without any impurity, are called intrinsic semiconductors. Examples Pure Germanium (Atomic weight 32) and pure Silicon (Atomic weight 14). Both are tetravalent. Intrinsic semiconductors, holes and electrons are Produced simultaneously and they act as charge carriers. In metals free electrons are the charge carriers.
Multiple Choice Questions on Semiconductors pdf
1. The energy gap between the conduction bond and valence band of a substance is of the order of 0.7 eV, then the substance is_______
(a) a conductor
(b) a semiconductor
(c) an insulator
(d) a super conductor
Answer : B
2. At ordinary temperature, an increase in temperature, increases the conductivity of_______
(a) a semiconductor
(b) a conductor
(c) a super conductor
(d) an insulator
Answer: A
Read : Solar Cell MCQs
3. The energy band gap is maximum in__________
(a) copper
(b) an insulator
(c) gernmanium
(d) a super conductor
Answer: B
4. Fermi energy is the____
(a) minimum energy of electrons in a metal at 0 K
(b) maximum energy of electrons in a metal at 0 K
(c) minimum energy of electrons in a metal at 0° C
(d) maximum energy of electrons in a metal at 0° C
Answer: B
5. The valence band and the conduction band of a substance overlap at ordinary temperatures. The substance may be_____
(a) ap-type semiconductor
(b) a conductor
(c) an insulator
(d) an n-type semiconductor
Answer: B
6. In an insulator_____
(a) the valence band is partially filled with electrons
(b) conduction band is partially filled with electrons
(c) conduction band is empty and the valence band is filled with electrons
(d) conduction band is filled with electrons and valence band is empty
Answer: C
7. When an n-n-p transistor is used as an amplifier, then______
(a) holes move from emitter to base
(b) electrons move from base to collector
(c) electrons move from collector to base
(d) electrons move from base to emitter
Answer: B
8. The electrical conductivity of a semiconductor increases When electromagnetic radiation of wavelength shorter than 2500 nm is incident on it. What is the band gap energy in eV for the semiconductor ? [h = 6.63 x 10‐³⁴ J-s]
(a) 0.9 eV
(b) 1.2 eV
(c) 1.8 eV
(d) 0.5 eV
Answer: D
9. A solar cell is basically a_____
(a) ap-type Ge semiconductor
(b) an illuminated n-p-n type transistor
(c) an intrinsic silicon semiconductor
(d) an illuminated silicon p-n junction diode
Answer: D
10. A potential barrier of 0.5 V exists across a p-n junction. What is the width of the depletion region if a constant electric field of magnitude 10⁵ V/m exists in the depletion region ?
(a) 3 umn
(b) 5 um
(c) 7um
(d) 4 um
Answer: B
Read : MCQs on Newton’s Law of gravitation
11. When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductor is called_____
(a) an n-type semiconductor
(b) ap-type semiconductor
(c) an intrinsic semiconductor
(d) an extrinsic semiconductor
Answer: B
12. In a transistor amplifier, the collector current is 5.5 mA for an emitter current of 5.6 mA. What is the current amplification factor of the transistor?
(a) 45
(b) 50
(c) 55
(d) 60
Answer: D
37. When the electrons leave the n material and enter the P material to fill up the holes, the process is called_________
(a) mixing
(b) diffusion
(c) doping
(d) depletion
Answer : B
38. When ap-njunction diode is forward biased it acts like_____
(a) a high resistance
(b) an ON switch
(c) an OFF switch
(d) a capacitor
Answer : B
39. In a halfwave rectifier, the output frequency is 50 Hz if the input frequency is 50 Hz. What is the output frequency of a fullwave rectifier for the same input frequency ?
(a) 50 Hz
(b) 100 Hz
(c) 25 Hz
(d) 75 Hz
Answer: B
40. When the resistance between p andn regions is very high then the p-n junction diode acts as_______
(a) an inductor
(b) a transistor
(c) a capacitor
(d) zener diode
Answer : C
41. Electric current is due to drift of electrons in_______
(a) metallic conductors
(b) semiconductors
(c) in both (a) and (b)
(d) insulators
Answer : C
42. If in ap-n junction diode, the drift current is less than the diffusion current in magnitude, then________
(a) p-njunction is reverse biased
(b) p-njunction is forward biased
(c) P-njunction is unbiased
(d) p and n regions are heavily doped
Answer: B
43. In a p- njunction, electric conduction takes place due to_______
(a) drift
(b) diffusion
(c) drift and diffusion
(d) barrier potential
Answer: C
44. When an ideal junction diode is reverse biased_______
(a) it acts like a short circuit
(b) it acts like a super conductor
(c) it acts like an open circuit
(d) it has a zero resistance
Answer: C
45. When an ideal junction diode is forward biased_____
(a) it acts as an open circuit
(b) it acts as a short circuit
(c) it acts as an insulator
(d) it has an infinite resistance
Answer: B
46. Zener breakdown Occurs only when______
(a) it is lightly doped
(b) the temperature is increa
(c)it is forward biased
(d) it is reverse biased
Answer: D
47. For the proper functioning of a zener diode as a voltage stabiliser it should be alway________
(a) forward biased
(b) reverse biased
(c) lightly doped
(d) connected in series with the load resistance
Answer : B
48. The value or tne zener current_______
(a) is determined by the zener voltage
(b) is always in the a microampere range
(c) does not depends upon the temperature
(d) is limited by the external circuit resistance
Answer : D
49. An LED is a_________
(a) forward biased p – njunction diode
(b) reverse biased p –n junction diode
(c) photodiode
(d) pin diode
Answer : A
50. The colour of light emitted by a LED depends upon______
(a) its forward bias
(b) its reverse bias
(c) the material of the semiconductor
(d) the amount of forward or reverse current
Answer: C
51.Once a zener diode is taken in its breakdown region, there Is not much change in its______
(a) current
(b) resistance
(c) voltage
(d) capacitance
Answer : C
52. Cneral purpose diode is more likely to suffer avalanche breakdown rather than zener breakdown because______
(a) its leakage current is small
(b) it has low reverse resistance
(c) it has strong co-valent bonds
(d) it is lightly doped
Answer: D
Hope this Multiple Choice Questions on Semiconductors pdf will helpful for your exams. mcqs on Semiconductors is a important topic in physics on which definitely one to two questions are come in exam. We also provide semiconductor mcq with answers pdf format.