Basic Electronics Engineering MCQ (Multiple Choice Questions)

1. What is the purpose of a transistor in electronic circuits?
a) To regulate voltage
b) To store data
c) To filter noise
d) To amplify or switch electronic signals

Explanation: Transistors are versatile semiconductor devices used for amplification and switching in electronic circuits.

2. Which type of semiconductor device acts as a one-way valve for electric current?
a) Diode
b) Inductor
c) Transistor
d) Capacitor

Explanation: A diode allows current to flow in one direction while blocking it in the reverse direction.

3. What is the purpose of a transistor in electronic circuits?
a) To filter noise
b) To amplify or switch electronic signals
c) To regulate voltage
d) To store data

Explanation: Transistors are versatile semiconductor devices used for amplification and switching in electronic circuits.

4. The fixed resistors restrict the flow of current up to what level?
a) Variable range
b) Any range
c) Certain level
d) Infinite level

Explanation: The resistance of the fixed resistors only restrict the flow of current to, a certain level. An ideal fixed resistor provides only constant resistances under any conditions. They cannot be varied.

5. Capacitance can be defined as the ratio of the electric charge on each conductor to what between them?
a) Potential difference
b) Electric difference
c) Potential energy
d) Voltage difference

Explanation: The capacitance is the ratio of the electric charge to the potential difference that why the units of the capacitance is coulomb/volts. The units of the electric charge are coulomb and the potential difference units are volts.

6. The ganged capacitor is the combination of what?
a) One variable capacitor and one polarized capacitor
b) One fixed capacitor and one variable capacitor
c) Two fixed capacitors
d) Two variable capacitors

Explanation: The ganged capacitor is the combination of the two variable capacitors. The two variable capacitors are connected together. A single shaft is used to rotate the variable ends of these capacitors which are combined as one.

7. What is the function of an inductor?
a) Makes the change in current
b) Allows the constant current
c) Oppose the change in current
d) Allows the change in current

Explanation: Inductors are the electronic devices that are used for opposing the change in current. Inductors have the simplest design among the all electronic devices. They are simply coil or windings of the wires.

8. If the inductance increases then which of the following don’t increase?
a) Cross sectional area
b) Frequency
c) No of windings
d) Permeability

Explanation: As, the inductance increases the no of winding increases. Inductance is directly proportional to permeability, cross sectional area and also length. The frequencies may or may not increase with increase in inductance.

9. Which of the following is the active transducer?
a) Capacitance
b) Thermistor
c) Resistance
d) Thermocouple

Explanation: Thermocouple is the active transducer as it produces the output by itself or by physical phenomena. The resistance, capacitance and the thermistor are the passive transducer as they cannot produce the output by their own and depends on external sources.

10. Which of the following is the most widely used inductance transducer?
a) Linear variable differential transformer
b) Linear variable transformer
c) Linear integrated transformer
d) Linear differential transformer

Explanation: The most widely used inductance transducer is linear variable differential transformer. It is well known as the LVDT. It has a primary coil and secondary coils and a rod shaped magnetic core that are positioned at the centrally inside the coil.

11. The temperature coefficient is linear over a large range of temperature for which material?
a) Copper
b) Tungsten
c) Platinum
d) Nickel

Explanation: The temperature coefficient is linear over a large range of temperature for platinum. This is the main advantage of the platinum over the nickel. Copper and tungsten are also not having this efficiency.

12. Hall effect transducers are the non-contact devices with what?
a) Low resolution
b) high resolution
c) No resolution
d) Large size

Explanation: Hall effect transducers are the non-contact devices with high resolution. They have low size. Other applications are in measurement of velocity, rpm, sorting, limit sensing etc.

13. Which of the following parameters is not useful for characterizing the thermistor?
a) Temperature constant
b) Resistance ratio
c) Dissipation constant
d) Time constant

Explanation: There are three parameters that determine the characteristics of the thermistor. They are time constant, resistance ratio and dissipation constant. The temperature constant have no effect on the characteristics of the thermistor.

14. Which of the following is the asymmetric crystalline materials?
a) Barium chloride
b) Barium nitrate
c) Barium titanite
d) Sodium nitrate

Explanation: The barium titanite is the compound having the asymmetric crystalline materials. Quartz and rochelle salt are the other compounds having the asymmetric crystalline materials.

15. Which of the following is an impurity added in a semiconductor to make it a P-Type semiconductor?
a) Indium
b) Gallium
c) Boron
d) Antimony

Explanation: Boron, Indium and Gallium are trivalent in nature and are added as impurities to form N-Type of extrinsic semiconductors. Antimony is pentavalent in nature and is used to form P-Type of semiconductors. Other examples for impurities added in extrinsic semiconductor to form P-Type are Phosphorous and Arsenic.

16. What is the layer called, when majority carriers of both the parts of the diode accumulate at the junction the layer?
a) Heterojunction Layer
b) Depletion Layer
c) Diffusion Layer
d) Combination Layer

Explanation: When holes leave the P-side, they leave behind a negative charge and when electron leaves the N-part, they leave behind a positive charge. The carriers accumulate in the junction. This accumulation on the junction is forms a layer termed as depletion layer.

17. In a given semiconductor at T = 300K, the electron concentration varies linearly from n = 1012 cm−3 to n = 1016 cm−3 over the distance from x = 0 to x = 3 μm and Dn = 35 cm2/s. What is the diffusion current density?
a) 187 A/m3
b) 211 A/m3
c) 170 A/m3
d) 145 A/m3

Explanation: We have, Jn=eDn $$\frac{dn}{dx}$$ = (1.6×10-19) *(35) *(1012 – 1016/0-3 x 10-4)
Hence, Jn = 187 A/m3.
Where e is charge on electron.

18. What type of device is a diode?
a) Isolated
b) inappropriate
c) Unidirectional
d) Bidirectional

Explanation: Diode is a device which allows current to flow only in one direction with ease. In the opposite direction, it far more difficult to conduct current for the diode. So, it can’t be acknowledged as a bidirectional device as that changes the properties and characteristics of diode. Hence, Diode is a unidirectional device.

19. Zener diode in reverse bias state has a controlled breakdown that allows current to keep the voltage close to which of the following?
a) Threshold voltage
b) Zener breakdown voltage
c) Conduction voltage
d) Knee voltage

Explanation: When the Zener diode is in reverse biased state, it can undergo breakdown after a specific value of voltage. After going into breakdown, for some values, the voltage level for different current level is same. This voltage level is a controlled one and referred as Zener breakdown voltage.

20. Which of the below is widely used, in the application of Zener diodes?
a) Shunt regulator
b) Series regulator
c) Rectifiers
d) Clamper

Explanation: Zener diodes have controlled breakdowns and also the voltage drop after the breakdown is close to the breakdown voltage even if the magnitude of current changes. From this we can conclude that, Zener diodes can be used for constant voltage requirement i.e. regulation of the voltage. Hence it is used as a Shunt regulator, whereas, normal diodes are used in rectifiers and in clamping circuits.

Chapterwise Multiple Choice Questions on Basic Electronics Engineering

Our MCQs focus on all topics of the Basic Electronics Engineering subject, covering all topics. This will help you to prepare for exams, contests, online tests, quizzes, viva-voce, interviews, and certifications. You can practice these MCQs chapter by chapter starting from the 1st chapter or you can jump to any chapter of your choice.

1. MCQ on Passive Circuit Components

The section contains multiple choice questions and answers on fixed resistors, variable resistors, capacitors, variable capacitors, fixed capacitors, and inductors.

2. Basic Electronics Engineering MCQ on Transducers

The section covers questions and answers on types of transducers, LVDT and electrical strain gauges, resistance thermometer and Hall effect, thermistor and thermocouple, and piezoelectric and photoelectric transducers.

3. Junction Diode and its Applications

The section contains MCQs on semiconductor theory and energy band structure, theory of PN-junction, and forward and reverse bias conditions, as well as Zener diode operation.

4. Questions on Integrated Circuits

The section contains multiple choice questions and answers on linear integrated circuits, including topics such as differential amplifier and circuit configuration, operational amplifier internal circuit, open-loop voltage gain as a function of frequency, and closed-loop frequency response.

5. Questions on Digital Electronics

The section covers questions and answers on digital electronics, covering Boolean logic operations, digital integrated circuits, binary coded decimal (BCD), and logic gates and networks.

If you would like to learn "Basic Electronics Engineering" thoroughly, you should attempt to work on the complete set of 1000+ MCQs - multiple choice questions and answers mentioned above. It will immensely help anyone trying to crack an exam or an interview.

Wish you the best in your endeavor to learn and master Basic Electronics Engineering!

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]