SOLID STATE DEVICES MCQS Part 4

SOLID STATE DEVICES MCQS Part 4

SOLID STATE DEVICES Multiple Choice Questions Part 4.

1 What happens to the photoconductive material when light strikes on it?
The conductivity of the material decreases
Nothing important happens
The conductivity of the material stays the same
The conductivity of the material increases

2 What type of diode is used for tuning receivers; operate with reverse bias and derived its name from voltage-variable capacitor?
Zener diode
Tunnel diode
Varactor diode
Crystal diode

3 What semiconductor material is used in the construction of LED?
Silicon
Germanium
Gallium
Gallium arsenide

4 What is approximately the sum of the number of protons and neutrons of an atom?
Atomic mass
Atomic number
Atom subscript
Valence shell

5 What is the number of protons in the nucleus or the number of electrons in an atom?
Atomic mass
Atomic weight
Atomic number
Free electrons

6 The charge of proton has the same value to that of an electron but
Opposite in sign
Greater in some cases
Lesser than in some cases
Usually not important

7 Mass of proton or neutron is times that of an electron.
⦁     1386
⦁     2000
⦁     1836
⦁     10

8 A photodiode which conducts current only when forward biased and is exposed to light.
LAD
LED
PIN
Photoconductor

9 What is the most commonly used color of an LED?
Orange
Blue
Red
Green

10 If the temperature of a semiconductor material increases, the number of free electrons
Decreases
Increases
Remains the same
Becomes zero

11 Varactor diode’s transition capacitance is directly proportional to the product of the permittivity of the semiconductor material and PN junction area but inversely proportional to its
Resistance
Voltage
Depletion width
Threshold voltage

12 A is a light-sensitive device whose number of free electrons generated is proportional to the intensity of the incident light.
Varicap
Photodiode
Schottky diode
LED

13 Which of the following is NOT one of the three distinct regions in the characteristic curve of a diode?
Forward bias region
Reverse bias region
Breakdown region
Saturation region

14 Another name for saturation current in a diode, which arises from the fact that it is directly proportional to the cross-sectional are of the diode.
Steady-state current
Constant current
Thermal current
Scale current

15 How much voltage would you measure across the base-emitter junction of a
silicon transistor at class A?
0 V
0.3 V
3.6 V
0.7 V

16 In an amplifier, the emitter junction is
Forward biased
Reverse biased
Grounded
Shorted

17 A manufacturer quotes in his specifications that a germanium diode conducts 50 mA at 1 volt. Determine the bulk resistance.
100 ohms
60 ohms
14 ohms
20 ohms

18 A silicon diode has a maximum allowable junction temperature of 150ºC. Find the maximum allowable power dissipation at 25ºC temperature if the diodes thermal resistance is 0.4 ºC/mW.
238 mW
313 mW
600 mW
117 mW

19 What is the principal characteristic of a zener diode?
A constant current under conditions of varying voltage
A high forward current rating
A constant voltage under conditions of carrying current
A very high PIV

20 What device whose internal capacitance varies with the applied voltage?
Zener diode
Photodiode
Tunnel diode
Varactor diode

21 The transistor configuration has the highest value of input resistance.
Common base
Common emitter
Emitter-stabilized
Common collector

22 A method of connecting amplifiers in cascade
Configuration
Coupling
Link
Stages

23 What is the largest region of a bipolar transistor?
Base
Emitter
Collector
P-region

24 A diode that has a negative resistance region and widely used in the design of oscillators, switching networks and pulse generators.
Hot-carrier diode
Tunnel diode
LED
Schottky diode

25 Refers to a three-layer diode.
Shockley diode
Schottky diode
Diac
Triac

26 Diode that operates in the reverse breakdown voltage and is used as a voltage regulator.
Varactor diode
PIN diode
Tunnel diode
Zener diode

27 Another name for metal-oxide semiconductor field effect transistor is
JFET
GFET
IGFET
Transistor

28 In enhancement-type MOSFETs, the region is used if the FET is to operate as an amplifier.
Triode region
Diode region
Cut-off region
Saturation region

29 In enhancement-type MOSFETs, the regions are used for operation as a
switch.
Triode and saturation
Cut-off and saturation
Saturation and active
Cut-off and triode

30 Unijunction transistor has three terminals, namely
Gate, cathode and anode
Grid, plate and cathode
Base 1, base 2 and emitter
Gate, base 1 and base 2

31 What two elements widely used in semiconductor devices exhibit both metallic
and nonmetallic characteristics?
Gold and silicon
Germanium and gold
Bismuth and galena
Silicon and germanium

32 What happens to the voltage drop across the diode when current flow increases
rapidly in a forward-biased diode?
Increases
Decreases
Becomes zero instantly
Remains relatively constant

33 What are the majority current carriers in the N-type silicon?
Free electrons
Holes
Bounded electrons
Protons

34 What diode gives off light when energized?
Photodiode
LED
Photoconductive cell
Tunnel diode

35 What are the solid state gallium arsenide devices that emit beam of radiant flux when forward biased?
LEDs
Photoconductive cells
IR emitters
Photodiodes

36 A graphical representation in transistor wherein the emitter current is plotted against the variable emitter base voltage VEB for constant value of collector-base voltage VCB.
Static curve
Input characteristic curve
Output characteristic curve
Semilog curve

37 When the collector current Ic is plotted against the collector base voltage at constant emitter Ie, the curve obtain is called
Output characteristic curve
Linear curve
V-I curve
Semilog curve

38 Eg for silicon is 1.12 eV and germanium is 0.72 eV. It can be concluded that
Less number of electron hole pairs will be generated in silicon than in germanium at room temperature
More number of electrons and hole pairs will be generated in silicon than in germanium at room temperature
High energy of charges is a property of silicon
The relationship of the two is not significant

39 Junction diodes are commonly rated by its
Maximum current and PIV
Inductance and PIV
Capacitance and maximum reverse current
Circuits resistance and maximum forward current

40 A special type of diode which is often used in RF switches, attenuators and various types of phase shifting devices is called
Zener diode
PIN diode
Tunnel diode
Varactor diode

41 A volt-ampere characteristic curve that describes the relationship of the output voltage of a transistor to its output current is a set input current.
Input characteristic
Output characteristic
Load line
Saturation curve

42 The use of coupling is particularly desirable in low level, low noise audio amplifier stages to minimize hum pick up from stray magnetic fields.
Transformer
Direct
RC
LC

43 The way in which the gain of an amplifier varies with the frequency is called
Logarithmic response
Frequency response
Voltage response
Phase response

44 The maximum rectification efficiency of a half wave rectifier is
⦁      81.2 %
⦁      40.6 %
⦁      20.6 %
⦁      25 %

45 The maximum rectification efficiency of a full-wave rectifier is
⦁      40.6 %
⦁      81.2 %
⦁      110 %
⦁      92 %

46 A coupled amplifier which has the major advantage of permitting power to be transported from the relatively high output impedance of the first stage to the relative low input impedance of the second stage.
RC coupling
Transformer coupling
Direct coupling
Stabilized coupling

47 Electron mobility property of silicon at 300 K is approximately equal to___m^2/V-s 
⦁      1.1
⦁      0.135
⦁      0.048
⦁      45

48 In a push-pull power amplifier, an input transformer can be used as a 
providing equal amplitude input signals opposite in polarity
Phase reversal
Phase-splitter
Limiter
Discriminator

49 If the line frequency is 60 Hz, the output frequency of a bridge rectifier is
30 Hz
60 Hz
120 Hz
240 Hz

50 Which of the following is considered a unipolar device?
Capacitor
Inductor
FET
BJT

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