Answer / jyoti sheoran

MODULATION IS A SCHEME WHICH ALTERS SOME CHARACTERISTICS OF
THE HIGH FREQUENCY CARRIER IN ACCORDANCE WITH THE LOW
FREQUENCY MESSAGE SIGNAL CALLED THE MODULATING SIGNAL.

THERE ARE THREE TYPES OF MODULATION :-

1). AMPLITUDE MODULATION(AM) :-
IN THIS TYPE OF MODULATION
FREQUENCY AND PHASE REMAINS SAME, ONLY THE AMPLITUDE
CHANGES.

2). FREQUENCY MODULATION(FM) :-
IN FM THE PEAK AMPLITUDE
AND PHASE REMAINS CONSTANT BUT AS THE AMPLITUDE OF THE
INFORMATION CHANGES, THE FREQUENCY OF THE CARRIER CHANGES
CORRSEPONDINGLY.

3). PHASE MODULATION(PM) :-
PM IS USED IN THE SAME SYSTEM
AS AN ALTERNATIVE TO FREQUENCY MODULATION. IN PHASE
MODULATION, THE PHASE OF THE CARRIER SIGNAL IS MODULATED TO
FOLLOW THE CHANGING VOLTAGE LEVEL OF THE MODULATING SIGNAL.

NEED FOR MODULATION :-

1: EFFICIENT RADIATION
2: FREQUENCY TRANSLATION
3: MULTIPLEXING
4: REDUCTION OF NOISE

why we multiply 11 in High Electric supply?(eg.11KV, 33Kv, 330Kv etc.)

3 Answers  

---

in cvt,there are two windings,1a,1n and 2a,2n.in my one project i use only one winding i.e.1a,1n. the other winding is not in use, so i connect it in open delta and want to close it by ibsertibg thermal resistor. the output of cvt is 132kv/115/sqrt3. plesae tell me exact value of resistor, so i may close it to avoid the resonance phenomenin. send me answer on this email adress please. aetcon-po@aetcon.com

0 Answers  

---

what is the pressure of vacuum circuit breaker

2 Answers  

---

How many types of relay are present in a VCB and ACB, what are the tests we can conduct on both breakers and how to set the relays values

2 Answers   Hyundai, Sodexo,

---

Why Lightning arrester used? Can we use piece of iron as a core material of transformer, if No, why? In CRGOSS material what is meaning of cold rolled grain oriented? Why Impegrenation of Transformer is done? Properties of Insulator? what is phase angle? Testing of transformers (Routine & Monthly)?

6 Answers   NTPC,

---

what is droop control?

0 Answers   BARC,

---

if receiving voltage is higher than sending ones what will be the effect of receiver

4 Answers  

---

in transformer the unit of power is in kva why?

4 Answers   Videocon,

---

what is 33 /11kv transformer bdv

8 Answers   NMDC, TPPL,

---

What is P.F? Formula for calculating PF in HT side?

1 Answers  

---

tell me about your project

1 Answers  

---

Where to use pt and where to use CVT

2 Answers  

---