Answer / bhadrappahr

Fluorescent tube is a gas discharge lamp. It consists of two
filamentary thermionic electrodes mounted at each end of
glass tube. The tube is filled with an inert gas like
mercury at low pressure and sealed. A high voltage is
necessary to start conduction through the tube. To obtain
this high voltage during starting an iron cored choke and
glow type starter are connected in series with filaments.
When the supply is switched ON an arc is struck between the
starter electrodes which causes a current to flow through
the choke and filaments. The filaments get heated up and
emit electrons. After a few seconds the starter electrodes
separates and due to this separation current is interrupted.
This interruption causes high voltage to be induced in the
choke which appears across the filaments of the tube
resulting in discharge through the tube. The gas inside the
tube is ionized and the ionized gas emits ultra-violet
radiation which is absorbed by the fluorescent material
coated inside of the tube this in turn emits light
radiations causing the tube to glow.

Answer / purusothaman.t

tube light starter:only for startung current limit purpose

A 60w bulb & a room heater are connected in series.if 60 w bulb is replaced by 100w then what will be the effect on heater out & why?

6 Answers  

---

while conducting an experiment why we connect the armature rheostat in maximum position and field rheostat in minimum position

1 Answers  

---

sir , what happen if we decrease ( approx 3 inch ) the lenth of shaft in 110KW Induction , three phase motor. actually a 110KW motor is couppled with star couplling to 120TR compressor. When we doing maintenance in compressor it is required to skid the motor backword and resulting dis- alightnment . so we want to change the tyre coupling in place of existing coupling. so it is required to cut off the rotor aprox 3 inch form driving side.

2 Answers  

---

generally in LT and MV motors we are using 3.5Coresx16,25,35,50 etc cable for supply.although motors is earthed at two point and having all protection.then why we are using that 1/2 core for earthing the motors.while in HT cable we are using only 3core cable for motor supply.generally lt and mv motors are delta connected and ht motors having star connection.whethere it is having any relation with winding connection( star or delta).all motors i am talking about are dol only.can anybody solve my confusion.thanks...

0 Answers  

---

1.why we are using metal oxide gapless block in lightning arrester,2.What is minimum and maximum rating of metal oxide blocks using in india

0 Answers   Areva,

---

---

when a three phase motor in running condition consumes 2A in each phase,and if one of the phase gets fails what will be the consumption in other two phases

4 Answers  

---

how to find out basic difference between ELCB,MCB AND RCCB on seeing the materials?

1 Answers   L&T,

---

what is the difference betn earthed and unearthed cables which is commanly used why?

2 Answers   Bhel, Power Grid,

---

in an industrical wiring, why we are using lighting DB and Power DB separately?

3 Answers  

---

Sir, I m 3rd year student 4m DCE and want to do internship in siemens or l&t or any other mnc related to electrical engineering. please tell me the procedure 4 same and oblige me

0 Answers  

---

in general it is observed in power stations, the tertiary winding is used in higher rating Y-Y auto transformer but not in Y-Y power transformer. is the tertiary winding is compulsory then why it is not using in power transformer 

0 Answers  

---

What is current chopping in CB?

1 Answers  

---