Which among the following is the most commonly used semiconductor?
Which of the following is compound semiconductor?
(d)All of these
Which of the following is created when trivalent impurities are added to a semiconductor?
(a) Free electrons
(c) Bound electrons
(d) Valence electrons
The relation between the number of free electrons in semiconductor and its temperature is given as
Which of the following diode is used in voltage regulator?
(a) Photo diode
(b) Zener diode
(d) p-n junction diode
Which material has a negative temperature coefficient?
A semiconductor placed at 0k, it will behave as
The forbidden energy gap for germanium is
(a) 0.12 eV
(b) 0.72 eV
(c) 1.11 eV
(d) 1.52 eV
In a middle of depletion layer of a reverse biased p-n junction, the
(a) electric field is zero
(b) potential is maximum
(c) electric field is maximum
(d) potential is 0
The output of OR gate is 1 when
(a) if both the inputs are 0
(b) if either or both inputs are 1
(c) only if both inputs are 1
(d) if either input 0
Why should a photodiode be operated at a reverse bias?
Draw the voltage-current characteristic for a Zener diode.
Suppose a pure Si crystal has 5 × 1028 atoms m–3. It is doped by 1 ppm concentration of pentavalent As. Calculate the number of electrons and holes. Given that ni =1.5 × 1016 m–3.
Explain briefly, which property of the characteristic enables us to use Zener diode as voltage regulator.
Draw the energy band diagram of n-type and p-type semiconductors.
A Zener of power rating 1 W is to be used as a voltage regulator. If Zener has a breakdown of 5 V and it has to regulate voltage which fluctuated between 3 V and 7 V, what should be the value of R, for safe operation (figure)?
Define the terms ‘potential barrier’ and ‘depletion region’ for a p – n junction diode. State how the thickness of the depletion region will change when the p-n junction diode is (i) forward biased and (ii) reverse biased.
With the help of a diagram, show the biasing of a light-emitting diode (LED). Give its two advantages over conventional incandescent lamps.
Draw the circuit diagram of a full-wave rectifier and explain its working. Also, give the input and output waveforms.
Distinguish between conductors, insulators, and semiconductors on the basis of the band theory of solids.