17-01-2015, 10:22 PM
PLS SEND MATERIAL TO ME FOR VIVA subjects like control systems ,mpmc, vlsi,stld,edc,ica,ac,dc .
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comprehensive viva questions for ece with answers
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PLS SEND MATERIAL TO ME FOR VIVA subjects like control systems ,mpmc, vlsi,stld,edc,ica,ac,dc .
25-03-2017, 10:24 AM
1. Define the rectifier?
The rectifier is an electronic circuit that converts the alternating signal into pulcating D.C
2. Define the full-wave rectifier?
This rectifier consists of a central transformer and two diodes. The central tap is connected to ground. [I.e] its potential is kept at zero.
3. Define the construction of full wave rectifier?
The diode 1 and diode 2 anodes are respectively connected to terminals A and B of the transformer secondary. The cathode of 2 diodes connected to the load.
4. What are the merits of Full Wave Rectifier?
The ripple factor is low when compared to the stop wave rectifier.
5. What are the main disadvantages of Full Wave Rectifier?
Here we use central tare transformers, so the cost is high.
6. What are the futures of Full Wave Rectifier [center-tap]?
Efficiency - 81.2% Ripple Factor - 0.48PIV - 2vm. Output Frequency - 2Days - 2.
7. Define photodiode?
It is one of the photo conducting devices of the union.
8. Define the photo-conductor effect?
When the incident light falls on the surface of a semiconductor, some adsorption of light by the semiconductor results in the generation of carriers resulting in an increase in conductivity. This effect is known as photo-conductive effect.
9. What are the two types of union?
I) Photo diode.
(Ii) Phototransistor
10. What are the devices that fall into the category of photo-conductor devices in bulk.
LDR, thermistor and sensor.
11. What are the applications of the photodiode?
1.Light detection system.
2.As an optical coupler.
3.Light switch operated.
4.Encoder.
5.Modulation.
12. Define the semiconductor diode?
When we attach a piece of material 'P' and material 'N', so that the crystal structure remains continuous at the limit. PN is formed. It's called a semiconductor diode.
13. Define the depletion layer?
A layer in which there are no free charge carriers. It consists of only non-compensated acceptor and donor ions.
14. Define the knee voltage?
The knee tension is the voltage at which the diode begins to drive.
15. What is the knee voltage for silicon and germanium?
Si = 0.6 v s Ge = 0.2 v
16. What are the other names of knee stress?
(I) threshold voltage.
(Ii) cutting voltage.
(Iii) compensation voltage.
17. What are the other names of the depletion region?
(I) space charge region.
(Ii) ionic region.
18. Why is a diode called a unidirectional device?
Because it only conducts current in the forward direction.
19. What is meant by reverse saturation current?
During reverse polarization, the reverse current produced by minority carriers is called the reverse saturation current.
20. What is the application of the diodes?
The diodes are used in rectifier, regulator, clipper, clamper, detector, etc ...,
21. What is the other name of the point contact diode?
Cut the wisker diode.
22. What is the transistor?
A particularly arranged semi-conductor offers low resistance to current flow in one portion while. The resistance of the thigh is offered in another portion. This type of arrangement of a semiconductor is called a transistor.
23. Why do we call a transistor as a bipolar component?
The transistor is called as a bi-polar component because it's operation depends on the majority and minority carriers.
24. Why do we call transistor as a transfer resistor?
Because, it transforms the low resistance path current to the high resistance path.
25. What are the types of transistors?
Type two: (i) Contact point (Defective is now out of use).
(Ii) Union Transistor (used now-a-day)
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