Answer / anil

cut in voltage of LED is higher bcoz LEDs are made up of
GaAs or GaAsP which has more threshold voltage.....

LEds are not used in rectifiers bcoz firstly they have more
cut in voltage so it creates a problem while rectifying low
voltages....and
secondly the PIV rating of LED is less than a typical Si
diode....so LED can get damaged during the negative portion
of the AC voltage....

Answer / raikwar rajesh kumar

The cut in voltage f LED is higher then diode because the
LED are a very important use of diodes in that they are the
most commonly used indicators.
All diodes emit radiation when a electron meets a
hole and falls into a lower energy state. The released
photon is dependant on the band gap. So, for particular
band gaps this released enery is chromatic.

what is phase reversal keying

1 Answers  

---

I'would like to know the type of questios asked for STA (senior technical assistant)interview in DRDO.whats the nature of the interview? whether theres HR and Technical interview?

2 Answers   DRDO, India Post,

---

why to study at university of new haven ?

0 Answers   Visa,

---

what does high Q(quality factor) value represent?

2 Answers  

---

Can any one please send me the hpcl question papers or pattern for ece branch please mail to sweetyastweety@gmail.com

0 Answers  

---

why qpsk is done for 45 135225315 not 0 90.270 360 degrees "degrees why "

0 Answers  

---

TELL ME 10 PRODUCTS OF TCS?

2 Answers   TCS,

---

State the different types of flip flop?

0 Answers  

---

Why do we use Multiple Access Schemes? What is the difference between FDMA, TDMA and CDMA?

1 Answers  

---

why the array is derived data type

2 Answers   Google,

---

Define what is the importance of valence shell and valence electrons?

0 Answers  

---

what is SNR?? WHY IT IS IMPORTANT IN COMMUNICATION NETWORK?

4 Answers   Wipro,

---