Answer / badal

SCR Full form of Silicon controlled rectifier.

Answer / vinee

A SCR is a unidirectional device that is applicable in high and medium power applications. It has 4 layers and 3 junctions. A positive gate pulse across gate and cathode turned it on. UJT is used for triggering.

Whereas a TRIAC is a bidirectional device that can be tuned on by applying both positive and negative gate pulses. It is more sensitive than an scr. It is also a 4 layer 3 junction device. DIAC is used for triggering..

They both can be used as lamp dinmers , heat control, speed control of induction motors according to their need.

Answer / engr. asad ali

SCR
It is four layered, three terminal semiconductor device.
The current is unidirectional, flowing only from cathode to anode.
Positive voltage is applied to gate to turn on.
A SCR can be turn off by rvercing current or reduce the voltage of anode below threshold value.
It conduct dc only.

Triac
It consist of two scr connected in opposite directions.
It has two main terminals (i.e 1 and 2) and a gate.
It operate on ac.
it can be turn off as SCR.

1)Why electric shock is feel ?? n in a Electric Train why we didnt feel that ? 2)What is the reason for transformer Noise ?? 3)What is relation b/w Transmission Lines & Communication Lines ? 4)Which material is used for making Transformer oil & How u measure its dielectric strength & Name the test ?

14 Answers   NTPC, Tata Power,

---

why transformer is giving some humming noise .....?

11 Answers   Electrotherm, JSW,

---

how to diffrentiate between ac & dc motors from a distance

5 Answers  

---

sigal phase supply is 230 v ac two phase supply is 415 v ac then why three phase supply having supply is 415 v ac why not 690v ac

2 Answers  

---

What is clock position of Transformer?what are the clock positions are there?and what is different of them?

0 Answers   Synergy,

---

what are the accessories need to be added while doing estimation for the following: 1.MCCB 2.MCB 3.ACB

0 Answers  

---

RATING OF LIGHTENING ARRESTER FOR 11 KV LINE IS 9 KV BUT WE KNOW THAT LIGHTENING ARRESTER IS USED FOR OVER VOLTAGE PROTECTION SO WHY NOT THE RATING OF LIGHTENING ARRESTER BE MORE THAN 11KV ???????????????//

5 Answers   Hakel,

---

In siemens S7-300 PLC, what is function and function block ? What is the difference between them ? When to use function and when to use function block ?

0 Answers  

---

why in an electrical lab a bulb connected to supply goes off slowly when the main supply is switched off?

2 Answers  

---

What is disadvanage if power factor goes to in leading..?

0 Answers  

---

How relay coordination has to be done? what are the inputs are required for this? Please explain this with calculation method?

0 Answers   Elektrotek,

---

what is the AC Plant and how can do the work with parts and picture tell us 150 Tr

0 Answers   Wipro,

---