Answer Posted / 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....

Tell me what is the max. Or min . Value of tv in msa to calculate r&r?

1119

---

Define what is the difference between active and passive filters?

2002

---

what is the significance of transistor number (exam. BC557,CIL188 etc) ?

2452

---

What is an amplifier?

1251

---

if i get a job in bsc .what are the main key duties to handle

2068

---

Define positive logic

1081

---

sir i want syllabus for junior engineer §ion engineer.

2118

---

4. How are the wattmeter readings equal in 2 Wattmeter method at UPF? Establish the condition mathematically?

1474

---

Noise with uniform power spectral density of n0w/hz is passed through a filter h (w) = 2 exp(-jwtd) followed by an ideal low pass filter of bandwidth bhz. What is the output noise power in watts?

1330

---

Explain the difference between a multiplexer and encoder? Also what is the between demultiplexer and decoder?

1281

---

Explain what is a state table?

1173

---

What is meant by cyclo-converter?

1084

---

What are the uses of flip flop?

1103

---

Explain conductivity, resistivity and resistance?

1081

---

Explain what are the universal logic gates?

1232

---