### SOLID STATE DEVICES Multiple Choice Questions Part 2.

1 The time taken by the diode to operate in the reversed condition from forward conduction.
Maximum power time
Reverse recovery time
Time allocation

2 Approximately, the atomic weight of germanium is
32
⦁      28.09
⦁      72.7
⦁      16

3 Atomic weight of silicon at 300 K is
⦁      28.09
⦁      72.7
⦁      5.32
⦁     16

4 An LED and phototransistor is equivalent to a/an
Thermocouple
FET
Optocoupler
Regulator

5 Optocoupler is otherwise known as
Laser
Photodiodes
Optoisolator
Photoconductive cell

6 When the emitter junction is forward biased while the collector junction is reverse biased, the transistor is at region.
Cut-off
Saturation
Active
Breakdown

7 When both emitter and collector junction are forward biased, the transistor is said to be at
region.
Active
Cut-off
Breakdown
Saturation

8 An equivalent circuit of a diode in which it is represented as a switch in series with a
barrier potential.
First approximation
Second approximation
Third approximation
Fourth approximation

9 Which of the following is the equivalent circuit for a diode for third approximation?
A switch only
A switch in series with a battery in series with a resistance
A switch in series with battery
A switch in series with a resistance

What is the charge of the hole?
Equal to that of a proton
Equal to that of an electron
Equal to that  of a neutron
Equal to zero

11 A silicon crystal is a/an of a semiconductor if every atom in the crystal is a
silicon atom.
Extrinsic
Intrinsic
P-type
N-type

12 With pnp voltage divider bias, you must use
Ground
Negative power supplies
Positive power supplies
Resistors

13 Two pn silicon diodes are connected in series opposing. A 5 V voltage is impressed upon
them. Find the voltage across each junction at room temperature when nVT= 0.052 V.
⦁      0.236 V, 3.2 V
⦁     4.764 V, 0.236 V
⦁      0.036 V, 4.964 V
⦁     3.21 V, 1.79 V

14 A half-wave signal has a period of
16.7 ms
8.3 ms
16.7 µs
8.3 µs

15 When doping increases, of a semiconductor decreases.
Impurity
Conductivity
Bulk resistance
Minority carrier

16 Which of the following has the least noise level?
FET
BJT
Triode
Tetrode

17 Which of the following has the highest input impedance
FET
BJT
MOSFET
Crystal diode

18 The frequency of a half-wave signal is
Twice the line frequency
Equal to the line frequency
One-half of the line frequency
One-fourth the line frequency

19 For a full-wave rectifier, the output frequency
Equals one-half the input frequency
Equals the line frequency
Equals two times the input
Is three times the line frequency

20 The averaged dc voltage of a half wave rectifier circuit is of the value of the peak input voltage.
⦁      63.6%
⦁      31.8%
⦁      4.8%
⦁      6.2%

21 The average dc voltage of a full wave rectifier circuit is of the value of the peak input voltage.
⦁      31.8%
⦁      48.1%
⦁      63.6%
⦁      1%

22 Typical leakage current in a pn junction is in the order of
µA
mA
nA
pA

23 The resistance of a forward biased pn junction is in the order of
fi
mfi
µfi
kfi

24 The removal by electronic means of one extremity of an input waveform is called
Filtering
Clamping
Amplifying
Clipping

25 Which of the choices below does not describe a clipper circuit?
Limiter
Amplitude selector
Slicer
Baseline stabilizer

26 The varactor diode is also called as
Voltage-variable capacitance
Varicap
Epicap
All of the above

27 What diode has no depletion layer
Varactor
Varistor
Schottky diode
Shockley diode

28 Varistors are used for line filtering to eliminate spikes and dips and is also called
Transient regulator
Transient limiter
Transient filter
Transient suppressor

29 Defined as random motion of holes and free electrons due to thermal agitation
Fission
Fusion
Diffusion
Ionization

30 The temperature coefficient of resistance of a semiconductor is
Positive
Negative
Zero
Infinity

31 A large signal amplifier which is biased so that collector current flow continuously during the complete electrical cycle of the signal as well as when no signal is present
Class A
Class B
Class AB
Class C

32 A large signal amplifier which is biased so that current is non zero for less than one-half cycle.
Class AB
Class C
Class A
Class B

33 A class amplifier stage operates with a small forward bias of the transistor so that some collector current flows at all times
A
B
AB
C

34 What factor is shown on a data sheet that tells how much you have to reduce the power of a device?
Power factor
Derating factor
Reactive factor
Reduction factor

35 The time it takes to turn off a forward-biased diode is called the
Forward recovery time
Reverse recovery time
Recombination
Turn-off time

36 A heavily doped semiconductor has
High resistance
No effect on the semiconductor characteristics
More heat dissipation
Low resistance

37 Gallium arsenide, aluminum arsenide and gallium phosphide are classified as
Elementary semiconductor
Secondary semiconductor
Insulators

38 A lightly doped semiconductor has
Low resistance
High resistance
No effect on a semiconductor
More heat dissipated behaviors

39 The property or ability of a material to support charge flow or electron flow
Resistance
Conductance
Resistivity
Permeance

40 What is also known as photodiffusion effect?
Dember effect
Skin effect
Destriau effect
Night effect

41 An effect that occurs within the entire bulk of a semiconductor material rather than in a localized region or junction
Silicon effect
Dember effect
Bulk effect
Destriau effect

42 The creation voltage in a conductor or semiconductor by illumination of one surface
Dember effect
Skin effect
Destriau effect
Night effect

43 What device uses a material catwhisker as its anode and is classified as a hot-carrier
diode?
PIN
Point-contact diode
Shockley diode
Crystal diode

44 What is the typical operating current of an LED?
50 mA
10 mA
20 mA
5 mA

45 At absolute zero temperature, a semiconductor behaves as a/an
Good conductor
Superconductor
Insulator
Variable resistor

46 Avalanche breakdown in a semiconductor takes place
When forward current exceeds a certain value
When potential barrier is reduced to zero
When reverse bias exceeds a certain value
When forward bias exceeds a certain value

47 A cold-cathode glow-discharge diode having a copper anode and a large cathode of sodium or other material.
Tunnel diode
BARITT diode
Anotron

48 A microwave diode in which the carriers that transverse the drift region are generated by minority carrier injection from a forward-biased junction instead of being extracted from the plasma of an avalanche region.
IMPATT
TRAPAT
BARITT diode
Esaki diode

49 What electronic circuit converts AC to DC where the DC output peak value can be greater than the AC input peak value?
Voltage multiplier
Rectifier
Clamper
Clipper

50 Which of the item below does not mean a VARACTOR diode?
VOLTACAPS
VARICAPS
Voltage variable capacitors
Variable resistance diode