Electronics Engineering

A latching circuit is a circuit with two stable states, which one can think of as 1 and 0, thereby being able to store one bit of information. In circuit diagrams, these are represented by cross-coupled NOR or NAND logic gates.

IF we use frequency modulation for transmitting video signal this can cause phase shifting .and eyes can percieve this distortion effect easly . and requires more bandwidth to send the signal .Color levels are adjusted by amplitude in TV .So it s more logic to use Amplitude modulation .

binary addition of two bits is called a half adder ,and of three bits is called a full adder to be more lucid in my explanation a half adder doesnot consider a carry generated from the previous added pair of binary numbers

consider an example :-

A=a1a2a3a4 + B=b1b2b3b4 = sum=s1s2s3s4

the actual addition procedure is a4 and b4 are added first then the sum is stored in s4 and the generated carry is added with a3 and b3 and the process continues

so addition of a4 and b4 where there is no input carry is carried out by half adder and the addition of c1+a3+b3 is carried out by full adder. but practiclly the first situation a4+b4 can be considered as a4+b4+0 so all the addition can be performed by full adder it self

truth table for both half adder

A B s c

0 0 0 0 0 1 1 0 1 0 1 0

1 1 0 1

for full adder

c1 A B s c

0 0 0 0 0

0 0 1 1 0

0 1 0 1 0

0 1 1 0 1

1 0 0 1 0

1 0 1 0 1

1 1 0 0 1

1 1 1 1 1

where s and c can be viewed as the sum and carry

on solving the k-map for full adder and half adder we can obtain the fuctions of sum and carry

A: No matter how many resistor of different value are inserted the current will remain the same for each. The voltage drop will vary with the difference in resistors and i a parallel path is found along the way the current will divide according to the resistors values

Check this link

http://www.dumpt.com/img/viewer.php?file=bd6b3mqsa66fhr6c76l1.bmp

a group of flip-flops sensitive to pulse duration is called latch whereas a group of flip-flops sensitive to pulse transition is called a register.

A Synchronous Sequential Circuit is a system whose behavior can be defined on the timing of their signals , where in the case of asynchronous sequential circuit depend upon the order in which its inputs signals change and can be affected at any instance of time .

(reference : M. Moris Mano)

Line trap also is known as Wave trap. What it does is trapping the high frequency communication signals sent on the line from the remote substation and diverting them to the telecom/teleprotection panel in the substation control room (through coupling capacitor and LMU).

This is relevant in Power Line Carrier Communication (PLCC) systems for communication among various substations without dependence on the telecom company network. The signals are primarily teleprotection signals and in addition, voice and data communication signals.Line trap also is known as Wave trap. What it does is trapping the high frequency communication signals sent on the line from the remote substation and diverting them to the telecom/teleprotection panel in the substation control room (through coupling capacitor and LMU).

This is relevant in Power Line Carrier Communication (PLCC) systems for communication among various substations without dependence on the telecom company network. The signals are primarily teleprotection signals and in addition, voice and data communication signals.

The Line trap offers high impedance to the high frequency communication signals thus obstructs the flow of these signals in to the substation busbars. If there were not to be there, then signal loss is more and communication will be ineffective/probably impossible.

A: Photocell and LED cannot work directly because these are different devices. But yes each independently can work as a unit all you need is some buffering.

is it ? are you sure ? but i know so many circuit where capacitor is connected with ac supply .

still , if u connected a capacitor to dc supply , then :

1. if it is in SERIES with the dc supply , it will block all the dc current as capacitor

provides infinite resistance to dc current .

application : where u want to block dc current.(simple high pass filter)

2. if it is in PARALLEL with the dc supply , it will not block dc current , but if any ac

current comes out from the supply , the ac current will go through the

capacitor , as capacitor provides small resistance to ac current.

application : a) where u want to block ac current.(simple low pass filter)

b) to filter the noise (ac components) of dc supply.

A cathode ray oscilloscope (CRO) is used to see the waveform of a repetitive electronic signal. The signal is amplified or attenuated as required and used to deflect an electron beam in the vertical direction. This electron beam is deflected in the horizontal direction at a suitable speed. The electron beam impinging on a phosphorescent screen enables the viewer to see the wave shape of the signal. The operation is similar to that of a TV.

You should answer this question yourself by doing a couple of examples using Ohm's law I=E/R (current equals voltage divided by resistance. Here they are: Base circuit: 10 volt supply feeding a 10 ohm resistor calculate the current... New circuit: 10 volt supply (voltage kept constant) feeding a 20 ohm resistor (increased resistance) calculate the current... Did the current increase, or decrease? This way you can prove to yourself the answer!

The operational amplifier is a device with two inputs, and one output. One input is called non-inverting, while the other is called inverting. Sometimes, there are two outputs, in which case one is also non-inverting and the other inverting.

Within the limits of the design of the operational amplifier and its circuit, the output will assume whatever state is necessary to make the two inputs equal to each other. The output goes in the same direction as the non-inverting input, or in the opposite direction as the inverting input.

Note that for the operational amplifer to work correctly, there needs to be some kind of feedback loop, usually from output to inverting input (we call this negative feedback), so that the output can track one of the two inputs in the ratio of the bridge that is setup in the circuit design.

for TEM u need to a magnetic field (H) linked to an electric field .for this u need to a J relative to E (E=sigma J). because [curl H = J] but optical fiber is dielectric wave guide and sigma is zero and u only have dD/dt so there isn't H linked to E.

See SSH and SSL

is the way in which information is percieved and processed.

advantage-its a base for all the digital modulation technique

disadvantage-

1.since amplitude keeps varying so there is noise associated with it.

2.due to nyquist criteria its require high bandwidth.

3.due to amplitude variation peek power of receiver also varies with it

nitesh

ohm

anode positive potential cathode negative potential

Electronics and Telecommunication is the mother branch of IT. This branch is having wide scope in the public sector, Private sector as well as in Government sector.

A capacitor will charge at a set time of 63% for one time constant and will continue to do so until fully charged which mathematically will never happen. therefore in the industry a 5 time interval is considered as fully charged.

A capacitor whose capacitance is variable (within some range). They are usually used to adjust resonant circuits or delay circuits.

The active region of a transistor is when the transistor has sufficient base current to turn the transistor on and for a larger current to flow from emitter to collector. This is the region where the transistor is on and fully operating.