Semi conductor devices practice · Mixed difficulty

Zener breakdown takes place if

Consider the following statements (A) and (B) and identify the correct answer:

(A) A zener diode is connected in forward bias, when used as a voltage regulator.

(B) The potential barrier of p-n junction lies between 0 V to 0.1 V.

An AND gate can be prepared by repetitive use of
(a) NOT gate $\,\,\,\,\,\,\,\,$ (b) OR gate $\,\,\,\,\,\,\,\,$ (c) NAND gate $\,\,\,\,\,\,\,\,$ (d) NOR gate

Given below are two statements:

Statement I: $\overline{\bar{A} \cdot \bar{B}}=A+B$

Statement II: $\overline{\bar{A}+{\bar{B}}}=A \cdot B$

Which of the following statement(s) is/are correct?

For a transistor to work as an amplifier

Which of the following statements is correct for proper working of zener diode?

A $p$-type material is electrically …….

The electrical circuit used to get smooth output from a rectifier circuit is called

A full wave rectifier is used to convert $50 {~Hz}$ ac to dc. Then the number of pulses per sec present in the rectified voltage is

The reverse bias in a junction diode is changed from $10 \, \mathrm{v}$ to $25 \, \mathrm{v}$ then the value of current changes from $30 \, \mu A$ to $80 \, \mu A$. The resistance of the junction diode will be $[\Omega]$

The correct relation between $\alpha$ (ratio of collector current to emitter current) and $\beta$ (ratio of collector current to base current) of a transistor is

Identify the incorrect statement regarding a superconducting wire

A semi conductor has an electron concentration of $8 \times 10^{13}$ per $\mathrm{cm}^3$ and a hole concentration of $5 \times 10^{12}$ per $\mathrm{cm}^3$. The electron mobility is $25000 \mathrm{~cm}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1}$ and the hole mobility is $100 \mathrm{~cm}^2 \mathrm{~V}^{-1} \mathrm{~s}^{-1}$. Then,

Identify the property which is not characteristic for a semiconductor?

Zener diode is used for

Avalanche breakdown in a $p - n$ junction diode is due to

A) For a diode the forward bias resistance is low as compared to the reverse bias resistance

B) In rectifier circuits capacitor input filters use large capacitors.

When $p - n$ junction diode is forward biased then

In p-n-p transistor circuit, the collector current is $10 \mathrm{~mA}$. If $90 \%$ of the holes reach the collector, find emitter and base currents.

The binary number 10111 is equivalent to the decimal number

Digital circuit can be made by repetitive use of this gate

On increasing the reverse bias to a large value in a $p - n\;$ junction, diode current

Assertion: A $N$ type semiconductor has a large number of electrons but still it is electrically neutral.
Reason: A $N$ type semiconductor is obtained by doping an intrinsic semiconductor with a pentavalent impurity.

A specimen of silicon is to be made P-type semi-conductor for this one atom of indium, on an average, $5 \times 10^7$ silicon atoms. If the number density of silicon is $5 \times 10^{22}$ atom $/ \mathrm{m}^3$. Then the number of acceptor atom per $\mathrm{cm}^3$ will be

In the binary number system $1+1=$

The minimum potential difference between the base and emitter required to switch a silicon transistor ‘ON’ is approximately

An n-p-n transistor operates as a common emitter amplifier, with a power gain of 60 dB. The input circuit resistance is $100\;\Omega$ and the output load resistance is $10\;k\Omega .$ The common emitter current gain $\beta$ is

Some statements are given about semi-conductors
a. Semi-conductor materials have crystalline structure and their atoms are bound together by covalent bonds
b. On adding suitable impurity even in small amounts, conductivity of semi-conductors increases appreciably.
c. Semi-conductor materials have sharply defined energy-levels for any electron belonging to a particular orbit.
d. Semi-conductors have negative temperature coefficient of resistance.

If no external voltage is applied across $P$-$N$ junction, there would be

The electrical conductivity of an intrinsic semiconductor at 0 K is