Expected questions on Basic Electronics Engineering|RRB JE|SSC JE|Industrial Extension officer
BASIC ELECTRONICS ENGINEERING
1. When a P-N Junction is reverse biased:
a. It offer high resistance…..
b. It breaks down
c. Its barrier potential decreases
d. Its depletion layer become narrow
2. A LED is made up of gallium phosphide semi conductor material emits …………….. radiations
a. Green
b. Red
c. Amber
d. Either green or red………
3. For a silicon PN junction, the barrier potential is about
a. 0.7 V…..
b. 0.001 V
c. 0.07 V
d. 1.7 V
4. The S.C.R is a …………..device
a. 2 layer 1 junction
b. 3 layer 2 junction
c. 4 layer 3 junction…..
d. 5 layer 4 junction
5. The best value of rectification efficiency for a full wave rectifier is around
a. 81%….
b. 75%
c. 48.5%
d. 99%
6. A pure semiconductor without any dropping
a. Intrinsic……
b. Extrinsic
c. Doping
d. Insulator
7. Germanium has
a. Ionic bond
b. Covalent bond………
c. Metallic bond
d. Molecular bon
8. Power diode differ from a signal diode is
a. Frequency
b. Voltage
c. Material
d. Doping…….
9. One of the following transistor is also known as double base diode
a. NPN
b. PNP
c. SCR
d. UJT…….
10. In CE amplifier I/P and O/P signals are:
a. 120° out of phase
b. 180° out of phase…..
c. In phase
d. 90° out of phase
11. Holding current of a SCR is …………….latching current
a. Equal to
b. More than
c. 10 times
d. Less than…….
12. One advantage of SMPS is
a. High out put ripple
b. Less sensitive to input voltage changes…
c. Noise
d. Higher size
13. Miller oscillator is an example for
a. Hartley oscillator
b. Colpitts oscillator
c. Cristal oscillator….
d. Wein bridge oscillator
14. One of the advantage of using free wheeling diode is
a. Improve input power factor….
b. Low input voltage
c. High output current
d. Perfect rectification