Why are functions of basis function similar to each other?

@devansh1221 said:

Can anyone post something on WiMax?

Can anyone post something on WiMax?

What is the difference between a Laptop and a Notepad. Explain in Electronic design.

@retry

@Omkarp

yeh dekho .. not sure how much it'll help
I am in no position to explain any acads to a panel .. only know basic phenomena behind these devices

1. Explain the working of a diode.
Diodes are devices that allow current to flow in one direction but oppose flow in the reverse direction. Could restate it as having low resistance in one direction/ high resistance in opposite. Most common forms of diodes are LEDs, Zener diodes, p-n junction diodes.

LEDs when biased have carriers re-combining. This results in them reaching lower/more stable energy states from their earlier states when they were separated. The energy released when reaching the more stable states is seen in the form of EM radiation of different frequencies .. this can be blue/red/UV/IR ..

p-n junction diodes contain two separate regions of semiconductor material doped differently to setup the p/n regions. They aren't joined together. The junction is where a depletion region is created by the re-combination of holes and electrons. This is what allows carriers to flow through easily in one direction and opposes the flow in the opposite.

Zener diode is an extension of this in that it will allow current to flow in the opposite direction at a reduced reverse biased voltage. This is where it is used to protect circuits. The phenomeon is Zener breakdown where a voltage difference over the small depletion region results in a large electric field which pulls out carriers in the opposite direction ( something similar to corona discharge, lightning .. might be an oversimplification .. ). Avalanche breakdown is also similar to this and both phenomenon occur at the same time. The difference between the two diodes is that ADs maintain a small voltage across them in breakdown but ZDs don't. Not very sure about this in more detail ..

Schottky diodes are also somewhat similar to p-ns but they have additional metal/silicon junction that gives faster switching times ... you could mention bias voltages of diodes .. silicon 0.7V, germanium 0.3V, SD 0.15V etc ..

2. Explain Zener diode, knee voltage, breakdown voltage. Applications.
Breakdown voltage is that voltage at which an insulator starts conducting. The limit in Zener diodes is Zener voltage .. avalanche point and all such terms are similar to this. Insulating material is ionized by application of strong voltage. Avalanche in diodes, Corona in fluids, Lightning/sparks in air ..

ZDs could be used to protect circuits from unexpected surges by placing them in reverse bias .. When a surge happens, it will breakdown because of its design easily, allow current to pass through it easily, protect the circuit. Current won't flow through the circuit because it will offer more resistance to current than your reverse biased ZD ..

3. Explain Impatt, Schottky, and Tunnel diode. Applications.
IMPATT, Tunnel used in high frequency electronics. iske aage jyada nahi pata ..
IMPATT uses the fact that an electron when accelerated to impact an atom can knock out an electron from it ... thus causing an avalanche effect

Tunnel diodes have a very thin p-n junction that allows quantum tunneling to kick in ..
iske jyada kahan kaise use hota hai .. pata nahi .. TBH never studied about them in any detail ..

5. What are Flip Flops?
Basic elements of memory .. bistable electronic device .. state can be controlled either by changing the level of input ( as in latches ) or my the edge of the input ( as in flip flops ) .. mostly basic wikipedia stuff ..

Frequently asked questions to me in interviews:

@sarvshwet The basics of engineering won't change. Thanks for sharing!

1.What do 0 and 1 in digital signify?
2.What are the different number system used in digital electronics?-IIM k

@sarvshwet said:

@abhiabhi15 here you go...but this file was made in 2007-08 not really sure if its still useful

@abhiabhi15

@abhiabhi15 said:

@sarvshwet not able to download.. xml problem.. please pm me .. TIA!!

@sarvshwet said:

had worked hard to collect a lot many question and answers for our field.....am uploading the entire ducument here.....its a 39 page long document....hope it helps some ppl.........

very helpful thread ..thank u all:)

The Intel 8085 is an 8-bitmicroprocessor introduced by Intel in 1977. It was binary compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built.
The "5" in the model number came from the fact that the 8085 requires only a +5-volt (V) power supply rather than the +5V, âˆ'5V and +12V supplies the 8080 needed. Both processors were sometimes used in computers running the CP/M operating system, and the 8085 also saw use as amicrocontroller, by virtue of its low component count. Both designs were eclipsed for desktop computers by the compatible Zilog Z80, which took over most of the CP/M computer market as well as taking a share of the booming home computer market in the early-to-mid-1980s.

Nice

CrookBond Says

A three-phase system is generally more economical than others because it uses less conductor material to transmit electric power than equivalent single-phase or two-phase systems at the same voltage (wiki)

Add to it that in a 3 phase system, one of the 3 phases is near it peak value at any moment of time. However, in a 2 phase or a single phase system, there are moments where you have zero values at some instant. A 4 phase system could also provide what a 3 phase can, however, there is very little gain and it also needs an extra wire for transmission. That's what makes a 3 phase system more ideal than the rest

3) Dont remember much, but I guess HLR is used for roaming and VLR is used for tracking. (this is wrong shayad :p).

HLR = Home Location Register. Associated with an MSC. Every cell user has a home circle, and the HLR connected to the MSC in the home circle has ur details.

VLR = When roaming to a different MSC (circle) the details need to be passed on to the MSC you are visiting. But how that MSC will know you are visitor? It will take details from HLR of your home MSC and copy the temporary TMSI nos etc into it's own VLR :)

Every MSC has an HLR and a VLR

CrookBond Says

A three-phase system is generally more economical than others because it uses less conductor material to transmit electric power than equivalent single-phase or two-phase systems at the same voltage (wiki)

well, then why dont we use 5phase or higher for transmission??? :::|::

1. how do you make two 2 submarines under water communicate with each other?

2. What is an antenna? what shud be the ideal length of an antenna to receive a good signal strength.

3. what are HLR and VLR?

1) Radio waves have a prob travelling through salt water, so the best solution is to raise the antenna above water and then carry on with the communication.
Otherwise there are several methods like:-
(i) Acoustic transmission - These use hydrophones.
(ii) VLF(very low freq) radio waves are sometimes used, but these prove ineffective at greater depths. For this VLF are replaced by ELF(extremely low frequency) radio waves which are effective at operating depths of the submarine.
(iii) Most effective i guess is the satellite communication as is the most widespread, wherein UHF, VHF and HF are used.

2) Antenna - An electrical device that converts Electrical currents into radio signals.
Length ka I dont remember dhang se, but a dipole antenna has two conductors going in opposite direction, and half-wavelength long.

3) Dont remember much, but I guess HLR is used for roaming and VLR is used for tracking. (this is wrong shayad :p).

1. how do you make two 2 submarines under water communicate with each other?

2. What is an antenna? what shud be the ideal length of an antenna to receive a good signal strength.

3. what are HLR and VLR?

Mr Ar Says

why do we use 3phase for power transmission? Anybody knows this answer?

A three-phase system is generally more economical than others because it uses less conductor material to transmit electric power than equivalent single-phase or two-phase systems at the same voltage (wiki)

oh!great thread.was looking out for something like this.
:cheers:

useful thread

why do we use 3phase for power transmission? Anybody knows this answer?

Moore's law: The no. of Transistors Doubles every 18 months in an IC

Damn great thread

gr8 work buddy...thanks...

Some of the questions I got this season in interviews are

1. What is hole theory?
2. What is avalanche effect?
3. Difference between CDMA and GSM?
4. What is GPRS? How does it work?
5. Have you heard of 4th generation mobile techlogy?
6. What is S/N ratio?
7. What is transponder?
8. What are the types of soldering?


Will add a few as I remember them...

Please post some good links if u can find ...

with inc rev bias elctrc field across p-n jn inc. at a certain rev bias the field imparts sufficient energy to a thermally gen carrie in crossing d jn. the carrier on colldng with a crystal ion on its way, disrupts a covlnt bnd prdcng nu elctron-hole pair. this process is cumulative nd produces an AVALANCHE of carriers in shprt tym, hence called avalanche effct. :)

little effort frm a to-be 2nd yr ECEian. hope dis helps.

Is there any1 who knows d logic for selection sort using 8085....

G!XX3R Says

Why does BBC radio reach all parts of the globe and not FM

BBC World Service - Wikipedia, the free encyclopedia

Why does BBC radio reach all parts of the globe and not FM

hi everyone
i need some help
i m goin for the xime interview and they r into asking questions abt the electronics sector in india
questions like which is the largest indian electronics company ? which is largest electronics company in india ? etc r very common
if anyone has any material related to the current scenario of the electronics sector in india ... plz post
i would be very grateful

hi all,

can you tell me any famous personality from Electronics background whom i can talk about in he interview?
( offcourse he should have an MBA, otherwise cross question will start coming...)

G!XX3R Says

Can any 1 explain the real technology behind 3G ?

3G - Wikipedia, the free encyclopedia

Compared to the older 2G and 2.5G standards, a 3G system must provide peak data rates of at least 200 kbit/s according to the IMT-2000 specification. Recent 3G releases, often denoted 3.5G and 3.75G, also provide mobile broadband access of several Mbit/s to laptop computers and smartphones.

The following standards are typically branded 3G:

the UMTS system, first offered in 2001, standardized by 3GPP, used primarily in Europe, Japan, China (however with a different radio interface) and other regions predominated by GSM 2G system infrastructure. The cell phones are typically UMTS and GSM hybrids. Several radio interfaces are offered, sharing the same infrastructure:

The original and most widespread radio interface is called W-CDMA.
The TD-SCDMA radio interface, was commercialised in 2009 and is only offered in China.
The latest UMTS release, HSPA+, can provide peak data rates up to 56 Mbit/s in the downlink in theory (28 Mbit/s in existing services) and 22 Mbit/s in the uplink.

the CDMA2000 system, first offered in 2002, standardized by 3GPP2, used especially in North America and South Korea, sharing infrastructure with the IS-95 2G standard. The cell phones are typically CDMA2000 and IS-95 hybrids. The latest release EVDO Rev B offers peak rates of 14.7 Mbit/s downstreams.

Can any 1 explain the real technology behind 3G ?

Please enter your PG credential and then download......(as many are unable to download)

sarvshwet has posted a pdf on page 4 of this forum. But i can't download it...

http://www.pagalguy.com/forum/prep-resources/21387-electronics-communication-engineering-core-interview-4.html

somebody plz help

Click and then download....

Not able to download this link.. :(
http://www.pagalguy.com/forum/prep-r...terview-4.html (Electronics and communication engineering core interview questions.)

Not able to download

http://www.pagalguy.com/forum/prep-r...terview-4.html (Electronics and communication engineering core interview questions.)

Please help me