Basic Electronics MCQ Question and Answer
Basic Electronics MCQ Question and Answer
21. A semi-conducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be
- A p-n junction
- An intrinsic semi-conductor
- A p-type semi-conductor
- An n-type semi-conductor
22. The transfer ratio beta of a transistor is 50. The input resistance of the transistor when used in the common emitter configuration is 1 kOhm. The peak value of the co current for an A.C. input voltage of 0.01 V peak is ?
- 100 microA
- 0.01 mA
- 0.25 mA
- 500 microA
23. The cause of the potential barrier in a p-n diode is ?
- Depletion of positive charges near the junction
- Concentration of positive charges near the junction
- Depletion of negative charges near the junction
- Concentration of positive and negative charges near the junction
24. In forward bias, the width of potential barrier in a p-n junction diode?
- increases
- decreases
- remains constant
- first increases then decreases
26. Which of the following when added acts as an impurity into silicon produced n-type semi conductor?
- P
- Al
- B
- Mg
27. In a junction diode, the holes are due to
- protons
- extra electrons
- neutrons
- missing electrons
29. The Keynesian theory of employment provides the
solution of?
- Frictional unemployment
- Disguised unemployment
- Cyclical unemployment
- Seasonal unemployment