HomeElectronics Multiple choice question MCQ online testElectronic Devices and Circuits MCQ Electronic Devices and Circuits MCQ Leave a Comment / Electronics Multiple choice question MCQ online test Share this 0% 35 Created on July 20, 2023Basic electronics Electronic Devices and Circuits MCQ Hint In the saturation region, the emitter-base junction is forward biased, the collector-base junction is also forward biased. This is the operating mode when no current flows through BJT. 1 / 31 Category: Electronics basics 1. In which region does BJT act as the OFF switch in electronic circuits? a. Cut-off b. Saturation c. Active d. Reverse saturation Hint MOSFET is preferred in digital and analog electronic circuits because it is faster than all other transistors. Also, it has a very high input impedance. 2 / 31 Category: Electronics basics 2. Which of the following type of transistor is preferred in digital and analog electronic circuits? a. BJT b. JFET c. MOSFET d. FET Hint At T = 0K, conductivity will be zero because donar level ionization is zero, so no free electron is there in the conduction band. Conductivity is measured when free electrons are present in the conduction band for conduction 3 / 31 Category: Electronics basics 3. What is the conductivity of an extrinsic type semiconductor electronic device at 0K? a. maximum b. zero c. can’t be determined d. minimum 4 / 31 Category: Electronics basics 4. Which of the following is not an electronic device? a. A mobile b. A computer c. A magnifying glass d. A keyboard Hint Silicon is mostly used to construct electronic circuits because silicon has a much higher PIV (Peak Inverse Voltage) than the other semiconductors. It is also very cheap. 5 / 31 Category: Electronics basics 5. Which of the following semiconductor is mostly used to construct electronic circuits? a. Silicon b. Germanium c. Selenium d. Tin Hint Solar cell is a photovoltaic cell. No external voltage is applied and solar cell responsivity is directly proportional to the wavelength of the incident light. It doesn’t produce dark current. 6 / 31 Category: Electronics basics 6. Which of the following is wrong about solar cell electronic devices? a. Solar cell responsivity is directly proportional to the wavelength of light b. It produces dark current c. t is a photovoltaic cell d. No external voltage is applied Hint Zener diode is a heavily doped diode. It is used in reverse bias. It has Zener breakdown. It is used in voltage regulators because it passes an excess amount of current in breakdown mode by maintaining constant voltage across the load. 7 / 31 Category: Electronics basics 7. Which of the following is true about Zener diode? a. It is lightly doped b. It is mostly used in voltage regulator electronic circuits c. It is used in forward bias d. It has avalanche breakdown 8 / 31 Category: Electronics basics 8. Which of the following is correct about semiconductors in electronic devices? a. Elemental semiconductors have direct band gap b. Compound semiconductors have indirect band gap c. Extrinsic semiconductors are injected with impurities d. Doping is done in Intrinsic semiconductors Hint Electron-hole pairs can be generated by increasing temperature or ionization or photo excitation. Impurity injection is done for doping of semiconductors. This process doesn’t generate electron-hole pairs. 9 / 31 Category: Electronics basics 9. Which of the following technique can’t be used for generating electron-hole pairs in electronic devices? a. Thermal excitation b. Impact ionization c. Photo excitation d. Impurity injection Hint Degenerative N-type and degenerative p-type semiconductors are used in tunnel diodes. Tunnel diodes are used in microwave electronic devices and circuits. 10 / 31 Category: Electronics basics 10. Which type of semiconductor is used in Tunnel Diode? a. Compound semiconductor b. Elemental semiconductor c. Degenerated semiconductor d. Extrinsic semiconductor Hint Recombination rate decreases when temperature increases because the electrons that are going to combine with holes in the valence bond are re-excited. 11 / 31 Category: Electronics basics 11. What is the effect of temperature on the recombination rate of electrons in electronic circuits? a. Recombination rate increases with increase in the temperature b. Recombination rate decreases with increase in the temperature c. Recombination rate is independent of temperature d. Recombination of electrons doesn’t occur in semiconductors 12 / 31 Category: Electronics basics 12. Which of the following is not a physical component of an electronic circuit? a. Capacitor b. Inductor c. Diode d. Temperature 13 / 31 Category: Electronics basics 13. Which of the following is false about Fermi-Dirac distribution function f(E) used to understand semiconductors in electronic circuits? a. f(E) is the probability of finding an electron in an energy level E b. When the temperature decreases f(E) also increases c. f(E) doesn’t give the number of electrons in a given energy level d. f(E) doesn’t give the number of energy levels with electrons 14 / 31 Category: Electronics basics 14. Which of the following is correct about photo diode electronic devices? a. P-N junction is connected in reverse bias. b. Electron-hole pairs are generated by impurity injection in depletion layer c. It is a photovoltaic cell d. No external voltage is applied Hint Electronic devices like MOSFET have the lowest turn-off times (nanoseconds). BJT has turn-off times in between nanoseconds to microseconds. IGBT and SCR have turn-off times of about 1 and 5 microseconds respectively. 15 / 31 Category: Electronics basics 15. Which of the following is the correct order of turn-off times? a. MOSFET < BJT < IGBT < SCR b. MOSFET < IGBT < BJT < SCR c. SCR < BJT < IGBT < MOSFET d. BJT < MOSFET < IGBT < SCR Hint Mass action law is related to the concentration of electrons and holes in a semiconductor. Degenerative type semiconductors show similar behavior to metal. So, Mass action law is not valid for them. 16 / 31 Category: Electronics basics 16. Mass action law is not valid for which type of semiconductors in electronic devices? a. Compound b. Elemental c. Degenerative d. Compensated 17 / 31 Category: Electronics basics 17. Forbidden Energy gap (EG) of a semiconductor in electronic devices depends on which of the following factors? a. Interatomic distance b. Material constant c. Electron affinity d. Recombination and Generation 18 / 31 Category: Electronics basics 18. Which of the following is wrong about threshold voltage (VT) in a MOSFET electronic circuit? a. If VT is less, channel form quickly for conductivity b. VT can be reduced by reducing oxide layer thickness c. VT is independent of ion implementation d. VT can be reduced by reducing substrate doping 19 / 31 Category: Electronics basics 19. Which of the following is not correct about semiconductors in electronic devices? a. Electrons are present below Fermi level in a semiconductor b. Degenerated semiconductors behave like a conductor c. Fermi level is independent of temperature and doping d. Pentavalent atoms are used in an n-type extrinsic semiconductor 20 / 31 Category: Electronics basics 20. Which of the following is wrong about P-N junction diodes used in electronic devices? a. They have three modes of operations b. They have dynamic resistance at low-frequency AC voltage c. They have diffusion capacitance at high-frequency AC voltage d. They can act as ON-OFF switches 21 / 31 Category: Electronics basics 21. Which of the following is correct about NMOS electronic circuits? a. It has N-substrate b. For inversion positive voltage is applied to the gate terminal c. For accumulation positive voltage is applied to the gate terminal d. NMOS has holes as the majority of carriers Hint When the depletion layer starts moving into the channel, due to the reverse bias of drain and substrate voltage, the inverted charge in the channel decreases from source to drain. 22 / 31 Category: Electronics basics 22. Which of the following is true about the depletion layer channel in an NMOS electronic circuit? a. Inverted change in the channel increases from source to drain b. Inverted charge remain constant c. Inverted change in the channel decreases from source to drain d. Potential in the channel decreases from source to drain Hint With a very high amount of doping in degenerative type semiconductors, atoms come closer. For this reason, the interatomic interaction cannot be neglected. So, the effective band gap becomes narrow. 23 / 31 Category: Electronics basics 23. Which of the following effects is responsible for violating the mass action law in degenerative type semiconductor electronic devices? a. Thermal effect b. Bandgap narrowing effect c. Lattice vibration effect d. Electronic drift effect 24 / 31 Category: Electronics basics 24. Which of the following is not a property of semiconductors used in electronic devices? a. They excite electrons b. They don’t emit light c. They have high thermal conductivity d. They have variable electrical conductivity 25 / 31 Category: Electronics basics 25. What is the conductivity of an extrinsic type semiconductor electronic device at 300K? a. Maximum b. Zero c. Can’t be determined d. Minimum Hint Band pass filter depends upon the value of the resistance and capacitance. In varactor diode, we can obtain capacitance by varying the input voltage. As capacitance becomes adjustable, it can be considered as an adjustable band pass filter. 26 / 31 Category: Electronics basics 26. Which of the following diode is used in adjustable band pass filter electronic circuits? a. Zener diode b. Varactor diode c. Tunnel diode d. Schottky diode 27 / 31 Category: Electronics basics 27. Which of the following is not correct about a step-graded junction in electronic devices? a. Diodes with step-graded junctions are slower than a normal diode b. They are designed with abrupt junction c. They are either p+ –n or p – n+ junction d. Depletion layer penetrates more into the lightly doped region 28 / 31 Category: Electronics basics 28. Which of the following is correct about Hall Effect in electronic circuits? a. Hall voltage is very weak in metals as compared to semiconductors b. Hall voltage is directly proportional to the charge density c. Hall voltage is inversely proportional to the intensity of the magnetic field d. Intrinsic semiconductor has a positive temperature coefficient of hall constant Hint Due to tunneling, a large number of electrons penetrate through the junction, so a large amount of current is produced. And as we are considering a special diode, we can control its I-V characteristics to improve the switching speed. 29 / 31 Category: Electronics basics 29. Which of the following diode is used in ultra-high speed switching electronic circuits? a. Zener diode b. Varactor diode c. unnel diode d. Schottky diode Hint LEDs need compound type semiconductors because they have direct band gap. In direct band gap, photons are easily generated when electrons release energy during recombination. 30 / 31 Category: Electronics basics 30. What type of semiconductor is used in LED electronic circuits? a. Intrinsic semiconductor b. Compound semiconductor c. Degenerated semiconductor d. Compensated semiconductor 31 / 31 Category: Electronics basics 31. In which of the following region does BJT act as the amplifier electronic device? a. Cut-off b. Saturation c. Active d. Reverse saturation Your score is LinkedIn Facebook Twitter VKontakte 0% Restart quiz Exit Anonymous feedback Thank you Send feedback Share this