the base has the least concentration of impurity

the emitter has the least concentration of impurity

the collector has the least concentration of impurity

all the three regions have equal concentrations of impurity

holes and conduction electrons recombine continuously throughout the material except in the depletion region.

new holes and conduction electrons are produced continuously throughout the material

new holes and conduction electrons are produced continuously throughout the material except in the depletion region

holes and conduction electrons recombine continuously throughout the material

MCQ Questions for Class 12 Medical Physics Semiconductor Electronics: Materials, Devices And Simple Circuits Quiz 16

Given:

$A$ and

$B$ are input terminals.
Logic

$1\, = \, > \, 5\, V$
Logic

$0\, = \, < \, 1\, V$
Which logic gate operation, the above circuit does?

0%
AND gate
0%
OR gate
0%
XOR gate
0%
NOR gate

In an unbiased p-n junction which of the following is correct?

0%
p- side is at higher potential than n-side
0%
n-side is at higher potential than p-side
0%
Both p-side and n-side are at the same potential
0%
Any of the above is possible depending upon the carrier density in the two sides

Explanation

In an unbiased

${\text{p - n}}$ junction, the

${\text{p - }}$ side has holes, i.e., equivalent positive charges. Hence, the

${\text{p - }}$ side remains at a higher potential than the

${\text{n - }}$ side.

The number of minority carriers crossing the junction of a diode depends primarily on the :

0%
concentration of doping impurities
0%
magnitude of potential barrier
0%
magnitude of the forward bias voltage
0%
rate of thermal generation of electron-hole pair

Explanation

The minority carriers in a diode are the ‘Holes’ and ‘Free Electrons’ for the

${\text{p - }}$ side and

${\text{n - }}$ side, respectively. The minority charge carrier’s movement depends on the thermal generation rate at the junction inside the diode. Which further depends on the rate of thermal generation of electron-hole pair.

So, the correct option is (D)

In the diagram, the input is across the terminals A and C and the output is across B and D. Then, the output is

0%
zero
0%
same as the input
0%
full wave rectifier
0%
half wave rectifier

Explanation

In the circuit, we can put an Alternating Current source in between the points

$A$ &

$C$ and we will connect the points

$B$ &

$D$ with an external resistance

$PQ$ with resistance

$R{\text{ }}\Omega$ .

When the voltage of the point

$A'$ is more than the point

$C'$ , the direction of current flow will be as follows-

$A' \to A \to B \to P \to Q \to D \to C \to C'$

When the voltage of the point

$A'$ is less than the point

$C'$ , the current will not flow because

${D_3}$ and

${D_4}$ both are in reverse bias.

Hence, the output will be a half-wave rectifier.

1999482_1445285_ans_82cdf835d3d2454d8e1dbfc4aa1eeb78.jpg

Current flowing in a Zener diode as shown in circuit: (Given diode is an ideal and $V_z = 4V$ )

0%
$0.4$ A
0%
$0.5$ A
0%
$0.9$ A
0%
$0.1$ A

Which of the following statements is true in case of zener diode?

0%
There is no similarity between forward chacteristic curve of a diode and zener diode
0%
a zener diode has sharp breakdown voltage
0%
A zener diode is always reverse biased
0%
The zener diode is a heavily doped diode

If the current constant for a transistor are

$\alpha$ &

$\beta$ then:

0%
$\alpha\beta=1$
0%
$\beta>1,\alpha<1$
0%
$\alpha=\beta$
0%
$\beta<1,\alpha>1$

The given truth table is

A	B	Y
0	0	0
1	0	1
0	1	1
1	1	0

0%
XOR gate
0%
NAND gate
0%
OR gate
0%
AND gate

What is the voltage across an ideal p-n junction diode for shown circuit?

0%
0.7 V
0%
1 V
0%
2 V
0%
None of these

Explanation

As the diode is connected in reverse bias in the circuit, the circuit will act like an open circuit. Hence, the voltage across the circuit will not change. It will remain

${\text{2 Volt}}$ .

So, option (C) is correct.

A zener diode having breakdown voltage equation to 15 V is used in voltage regulator circus shown in figure the current through diode is :

0%
100 mA
0%
95 mA
0%
150 mA
0%
195 mA

Explanation

The current through the load resistance,

${{I}_{1}}=\frac{{{V}_{zener}}}{{{R}_{Load}}}=\frac{5}{1\times {{10}^{3}}}=5\times {{10}^{-3}}A$

The current through the

$150\Omega$ resistance,

${{I}_{2}}=\frac{E-{{V}_{zener}}}{R}=\frac{\left( 20-5 \right)}{150}=\frac{15}{150}=0.1A$

Clearly, the Zener current,

${{I}_{zener}}={{I}_{2}}-{{I}_{1}}=\left[ 0.1-\left( 5\times {{10}^{-3}} \right) \right]A=95mA$

Option (B) is correct.

From the Zener diode circuit shown in figure, the current through the Zener diode is

0%
$34mA$
0%
$31.5mA$
0%
$36.5mA$
0%
$2.5mA$

Explanation

The current through the load resistance,

${I_1} = \frac{{{V_{zener}}}}{{{R_{Load}}}} = \frac{{50}}{{20 \times {{10}^3}}} = 2.5 \times {10^{ - 3}}A$

The current through the

$5{\text{k}}\Omega$ resistance,

${I_2} = \frac{{E - {V_{zener}}}}{R} = \frac{{220 - 50}}{{5 \times {{10}^3}}} = 34 \times {10^{ - 3}}A$

Clearly, the Zener current,

${I_{zener}} = {I_2} - {I_1} = \left( {34 - 2.5} \right) \times {10^{ - 3}}A = 31.5mA$

Option (B) is correct.

The charge in emitter current of a PNP transistor is 'x' and the corresponding change in the base current is 'y'. The

$\beta$ factor of the transistor is

0%
$\dfrac{x}{y}$
0%
$\dfrac{x-y}{x}$
0%
$\dfrac{x-y}{y}$
0%
$\dfrac{x+y}{y}$

Explanation

We have,

$\beta = \left( {\frac{{\Delta {I_C}}}{{\Delta {I_B}}}} \right) = \left( {\frac{{\Delta {I_E} - \Delta {I_B}}}{{\Delta {I_B}}}} \right) = \frac{{x - y}}{y}$

Zener diode is used as

0%
Half wave rectifier
0%
Full wave rectifier
0%
ac voltage stabilizer
0%
dc voltage stabilizer

In the given circuit, the current through the resistor

$2 k \Omega$ is:

0%
$2 m A$
0%
$6 m A$
0%
$1 m A$
0%
$18 m A$

The following logic gate circuit in equivalent to an

0%
NAND
0%
OR
0%
XOR
0%
NOT

Explanation

The inputs are

$A$ and

$B$ .

After going to

${G_1}$ ,

$OR$ gate, the output is

$A + B$

After going to

${G_2}$ ,

$NAND$ gate, the output is

$\overline {A.B}$

In the

${G_3}$ , the inputs are

$A + B$ &

$\overline {A.B}$ . Hence, the output will be

$(A + B).(\overline {A.B} )$ .

After doing the Boolean Algebra we can get the output truth-table as follows-

$0,1,1,0$

This is the truth table of

$XOR$ gate.

An input voltage

$V_i$ of

$0.20 \,V$ is applied to an operational amplifier connected as shown in the diagram. What is the output voltage

$V_0$ ?

0%
$0.20 \,V$
0%
$1.2 \,V$
0%
$0.80 \,V$
0%
$8.0 \,V$

Explanation

The voltage gain,

$V' = \frac{{{V_0}}}{{{V_i}}} = 1 + \frac{{{R_{feedback}}}}{{{R_{load}}}}$

So,

$\frac{{{V_0}}}{{{V_i}}} = 1 + \frac{{10k\Omega }}{{2k\Omega }} = 1 + 5 = 6$

Now, the output voltage,

${V_0} = {V_i} \times 6 = \left( {0.2 \times 6} \right){\text{ Volt}} = 1.2{\text{ Volt}}$

ASCII and EBCDIC are the popular character coding systems. What does ASCII stand for?

0%
American Stable Code for International Interchange
0%
American Standard Case for Institutional Interchange
0%
American Standard Code for Information Interchange
0%
American Standard Code for Interchange Information

The figure shown the function of

0%
$OR$ gate
0%
$NAND$ gate
0%
$XOR$ gate
0%
$AND$ gate

Explanation

In the given circuit,

${y_1} = {\text{A}}{\text{.B}}$ and

${y_2} = {\text{B}}{\text{.C}}$ . So, the final output after passing through the

$NOR$ gate is-

${\text{Q}} = {\text{ }}\overline {{\text{A}}{\text{.B}} + {\text{B}}{\text{.C}}}$

If we do the Boolean algebra, we will get the truth-table as a

$XOR$ gate.

The dc common emitter current gain of a n-p-n transistor is

$50$ . The potential difference applied across the collector and emitter of a transistor used in CE configuration is,

$V_{CE}=2V$ . If the collector resistance,

$R_C=4k\Omega$ , the base current

$(I_B)$ and the collector current

$(I_C)$ are?

0%
$I_B=10\mu A, I_C=0.5mA$
0%
$I_B=0.5\mu A, I_C=10mA$
0%
$I_B=5\mu A, I_C=1mA$
0%
$I_B=1\mu A, I_C=0.5mA$

In the circuit diagram of zener diode as shown in figure, when the value of

$V_0$ is

$8$ volt, the current through zener diode s

$i_1$ and when

$V_0$ is

$16$ volt, the corresponding current is

$i_2$ . Find the value of

$(i_2 - i_1)$ . (Zener breakdown voltage =

$V_2 = 6V$ )

0%
zero
0%
$5.0 \, mA$
0%
$1.5 \, mA$
0%
$8 \, mA$

Explanation

For

$V_0 = 8$ Volt

$i_0 = \dfrac{8 - 6}{1000} = 2mA; i_2 = \dfrac{6}{4000} = 1.5 \,mA$

$\therefore i_1 = (2 - 1.5) = 0.5 \,mA$

for

$V_0 = 16$ Volt;

$i'_0 = \dfrac{10}{1000} = 10 \,mA' i'_2 = 1.5 \,mA$

$\therefore i'_1 = 10 - 1.5 = 8.5 \,mA$

$\Rightarrow i'_1 - i_1 = 8 \,mA$
1245074_1612447_ans_6032be95412d4878bf40cada30c11472.png

$n$ -type semiconductor when all donor states are filled, then the net charge density in the donor states becomes

0%
$1$
0%
$< 1$
0%
$< 1 ,$ but not zero
0%
zero

Explanation

The major charge carriers in a

${\text{n - }}$ type semiconductor are electrons. When all donor states are filled, then the net charge density in the donor states becomes less than

$1$ because of all the negative charges,

But, it can not be equal to zero.

In the circuit given A, B and C are inputs and Y is the output. The output of Y is:

0%
Low for all low inputs
0%
High for all the high inputs
0%
High for all the low inputs
0%
None of these

Explanation

The inputs are

$A$ and

$B$ .

After going to

$NOR$ gate, the output is

$\overline {A + B}$

After going to

$AND$ gate, the output is

$\overline {A + B} .C$

If we do the truth-table, we will find out that the output is always low for every case.

An incomplete sentence about transistors is given below:
The emitter .............. junction is and the collector............... junction is . The appropriate words for the dotted empty positions are, respectively,

0%
'collector' and 'base'
0%
'base' and 'emitter'
0%
'collector' and 'emitter'
0%
'base' and 'base'

In a transistor,

0%
the emitter has the least concentration of impurity
0%
the collector has the least concentration of impurity
0%
the base has the least concentration of impurity
0%
all the three regions have equal concentrations of impurity

Which logic is used to select the proper path out of two or more alternative paths in the program logic?

0%
Sequence logic
0%
Iteration logic
0%
Selection logic
0%
None of these

In a p-n junction,

0%
new holes and conduction electrons are produced continuously throughout the material
0%
new holes and conduction electrons are produced continuously throughout the material except in the depletion region
0%
holes and conduction electrons recombine continuously throughout the material
0%
holes and conduction electrons recombine continuously throughout the material except in the depletion region.

This component is required to process data into information and consists of integrated circuits.

0%
Hard disk
0%
RAM
0%
CPU
0%
ROM

An adder which adds three binary digits and outputs a result bit and a carry bit is referred as

0%
Half adder
0%
Quarter adder
0%
Full adder
0%
None of these

The electrical conductivity of pure germanium can be increased by.

0%
increasing the temperature
0%
doping acceptor impurities
0%
doping donor impurities
0%
irradiating ultraviolet light on it.

Let it, it and it, represent the emitter current, the collector current and the base current respectively in a transistor. Then

0%
it is slightly smaller than it
0%
it is slightly greater than it
0%
is is much smaller than it
0%
it is much greater than it

In a normal operation of a transistor,

0%
the base-emitter junction is forward-biased
0%
the base-collector junction is forward-biased
0%
the base-emitter junction is reverse-biased
0%
the base-collector junction is reverse-biased.

The current amplification factor for common base circuit of a transistor is

$0.$ When emitter current is2mA then base current is:

0%
$2.1 \mathrm{mA}$
0%
$0.2 \mathrm{mA}$
0%
$0.19 \mathrm{m} \mathrm{A}$
0%
$1.9 \mathrm{mA}$

CBSE Questions for Class 12 Medical Physics Semiconductor Electronics: Materials, Devices And Simple Circuits Quiz 16 - MCQExams.com

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Practice Class 12 Medical Physics Quiz Questions and Answers

CBSE Questions for Class 12 Medical Physics Semiconductor Electronics: Materials, Devices And Simple Circuits Quiz 16 - MCQExams.com

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Practice Class 12 Medical Physics Quiz Questions and Answers

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