Question { Infosys, 36877 }

What do you mean by an ideal voltage source?

Answer

IT HAS A ZERO SERIES IMPEDANCE . IT IS ABLE TO PROVIDE A SAME VOLTAGE ACROSS ALL THE LOADS . IT HAS NO ANY LOSSES OR NO ANY POWER DISSIPATION .........

Question { 6312 }

an oscillator is associated with an basic amplifier for
producing oscillations,for production of oscillations the
amplifier needs some input voltage but under the oscillation
condition the input voltage is zero,why?

Answer

it is happen by the random electrons which is present in the amplifier. random electrons present in resistor .this random electrons will produce small amount of current in amplifier.this small current is amplify by the amplifier. And in this amplifier has a positive feedback so o/p of amplifier will amplify until the oscillation start. phase shift of input and output will be same in oscillation.

Question { Genco, 20822 }

MAN SHOCKED DUE TO CURRENT OR VOLTEAGE

Answer

man is shocked by current bcoz current is the flow of
electron and voltage is the potential level between two
points ...........
for e.g. gun fire bullet when bullet enter in our body then
it harmful and we are bleeding but after some times when
bullet in our body then it is not more harmful to us compare
to when it was enter in our body .............
so man is shocked by current ......

Question { Ericsson, 17426 }

What is the GSM fundamental?

Answer

gsm stands for global system for mobile .
in this system particular area is divided into a cluster
1 cluster is called a 7 cell this cell are arranged in hexagon shape. so we can use frequency reuse concept . in each cell there is a one bts for handling calls in that area.in our mobile sim(subscriber identification module) is there.when we are calling then mobile will send the signal to bts is the up link and bts send this signal via bsc,msc,hlr,vlr,auc,eir,pstn in sequence in this sequence our completely bio-data it will check and when authentication is done then it will transfer our call to our called user. when bts send signal to our called user from it's nearby area then the signal between bts and called user is down link.

Question { NTPC, 37147 }

What is the reason that sometimes we get network busy
message in mobiles while attempting a call?

Answer

gsm can handle 18 to 20 calls at a time in a second where as a cdma can handle 30 to 32 call at a time in a second .
when capacity of call handling is increases more then it's range then bts will handle only those call which are in process and it will reject those calls which are remaining.
when call handling capability increases more then the it's range then bts will send a signal to msc(mobile switching center). msc is programmed by a particular software. controller is present in the msc it will read the signal which is sent by bts then it will send a new signal to bts in the form of msg. "network is busy " and bts will send us this signal to our mobile. whenever this things is happen the bts will send signal to msc and msc will rply.msg. is depends on the programming we can also use this type of msg. "out of coverage:, "the no is not available " etc... msg. depending on the programming ..........

Question { 6486 }

what is isdn.

Answer

INTEGRATED SERVICE AND DIGITAL NETWORK .
IT IS USED IN E-MAIL , FAX, DATA TRANSFER ,VIDEO CHATTING ,.
IT IS a high-speed communications network which combines voice, data and video into single cables.An advanced, high-capacity wireline technology used for high-speed data transfer.

Question { 8359 }

what is setup time and hold time for a flip flop??

Answer

when we are giving a clock pulse to flip flop then it will produce output. time require between giving a clock pulse and producing output is called the setup time after producing output how much time it should be hold the output it is called the hold time.in another way we can say that
in rising edge in clock pulse it is called setup time and the time between rising edge and falling edge is called the holding time.

Question { GTL, 26722 }

What can be the reasons of a Call drop?

Answer

>call is drop occur when you are moving cell to cell , cell
to msc .
>when load on the bts is more than it could be not available
for accepting your call on that time.
>when you are in traffic area then also load on the bts is
high so call drop would be possible.
>when user moving from 1 cell to another cell than call will
be continue as before but in another cell is busy to
handling more no . of user so than it will be not able to
accept your call so call will be drop

Question { 4852 }

what is ISDN?

Answer

ISDN (Integrated Services Digital Network) is a set of CCITT/ITU standards for digital transmission over ordinary telephone copper wire as well as over other media. Home and business users who install an ISDN adapter (in place of a telephone modem) receive Web pages at up to 128 Kbps compared with the maximum 56 Kbps rate of a modem connection. ISDN requires adapters at both ends of the transmission so your access provider also needs an ISDN adapter. ISDN is generally available from your phone company in most urban areas in the United States and Europe. by using it we can fax,sending mail ,voice, video calling ,watching movie et.c services are available on it .

Question { 5984 }

difference bw latch & flip flop?

Answer

latch is used for temporary storage device it has no require
any gate pulse but flip flop has required gate pulse when we
are give it to the gate pulse than we get the output at q or
q' output port

Question { 12015 }

why use -48 volt DC power in telecom?

Answer

it is used for removing noise.............
because noise will be not affected more in -ve level so -48v dc is used for removing noise

Question { 5153 }

What is Erlangs? What is meant by GoS?

Answer

erlangs means unit of traffic which is used in
telecommunication network

Question { 5089 }

Which channel(s) is used for SMS?

Answer

SDCCH= STABD ALONE DEDICATED CONTROL CHANNEL
SACCH= SLOW ASSOCIATED CONTROL CHANNEL

Question { 21547 }

how there is a 180 degree phase shift in output signal of CE
amplifier?

Answer

if we want to amplify a particular signal then it will be
putting in the center of the load line. then we get the
complete 360 signal amplification .
there are four types of amplifier class -a,b,c,ab
.
so in class a amplifier it will be provide full signal
amplification in c.e
bcoz the signal place in the mid of the load line so it will
be provide full signal amplification and output is 180
phase shifted to the input ..............

Question { 9542 }

what is the meaning of 8 bit processors???????/

Answer

Ritika mam.......if processor will divide data into two parts than
definately it would have time....to make it.. .but if data bus and address bus is larger than it doesnt need to divide in two or more parts so it has not any extra time to do this so time will be reduced andd meanig of time reduced...so speed would be definately increased....i think u havent got any concept about arm processor so first know about it thane tell me i m wrong or right....maidammmmm