Semiconductor Diode Model Test(1st)

A crystal diode utilises ___________ characteristic for rectification

1 Mark(s)

reverse
forward or reverse
forward
none of the above

A crystal diode has

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none of the above
one pn junction
three pn junctions
two pn junctions

If the PIV rating of a diode is exceeded, ___________

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the diode conducts poorly
the diode behaves like a zener diode
none of the above
the diode is destroyed

The PIV rating of a crystal diode is ___________ that of equivalent vacuum diode

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the same as
more than
none of the above
lower than

A crystal diode is a ___________ device

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linear
none of the above
non-linear
bilateral

A zener diode is destroyed if it___________

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carrier more than rated current
is forward biased
none of the above
is reverse biased

The ___________ filter circuit results in the best voltage regulation

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capacitor input
resistance input
none of the above
choke input

If the a.c. input to a half-wave rectifier is an r.m.s value of 400/√2 volts, then diode PIV rating is ___________

1 Mark(s)

none of the above
400 V
400 x √2 V
400/√2 V

A zener diode is always ___________ connected.

1 Mark(s)

either reverse or forward
none of the above
forward
reverse

___________ rectifier has the lowest forward resistance

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vacuum tube
gas tube
none of the above
solid state

For the same secondary voltage, the output voltage from a centre-tap rectifier is ___________ than that of bridge rectifier

1 Mark(s)

twice
one-half
thrice
four time

When a crystal diode is used as a rectifier, the most important consideration is ___________

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forward characteristic
PIC rating
reverse characteristic
doping level

A zener diode has ___________ breakdown voltage

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sharp
undefined
zero
none of the above

A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8:1, what is the peak load voltage? Ignore diode drop.

1 Mark(s)

27.5 V
42.5 V
86.5 V
30 V

The doping level in a zener diode is ___________ that of a crystal diode

1 Mark(s)

less than
the same as
none of the above
more than

A crystal diode has forward resistance of the order of ___________

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Ω
MΩ
none of the above
kΩ

The knee voltage of a crystal diode is approximately equal to ___________

1 Mark(s)

barrier potential
breakdown voltage
applied voltage
forward voltage

The d.c. resistance of a crystal diode is ___________ its a.c. resistance

1 Mark(s)

less than
the same as
none of the above
more than

In the breakdown region, a zener didoe behaves like a ___________ source.

1 Mark(s)

constant current
constant resistance
none of the above
constant voltage

A zener diode is ___________ device

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a linear
an amplifying
none of the above
a non-linear

When the crystal current diode current is large, the bias is ___________

1 Mark(s)

inverse
forward
poor
reverse

The maximum efficiency of a half-wave rectifier is ___________

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81.2%
40.6%
50%
25%

The PIV rating of each diode in a bridge rectifier is ___________ that of the equivalent centre-tap rectifier

1 Mark(s)

four times
twice
one-half
the same as

A crystal diode is used as ___________

1 Mark(s)

a voltage regulator
an oscillator
a rectifier
an amplifier

The ratio of reverse resistance and forward resistance of a germanium crystal diode is about ___________

1 Mark(s)

1000 : 1
100 : 1
40000 : 1
1 : 1

There is a need of transformer for ___________

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none of the above
half-wave rectifier
centre-tap full-wave rectifier
bridge full-wave rectifier

A series resistance is connected in the zener circuit to___________

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none of the above
protect the zener
properly reverse bias the zener
properly forward bias the zener

The disadvantage of a half-wave rectifier is that the___________

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output is difficult to filter
components are expensive
diodes must have a higher power rating
none of the above

If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ___________ biased.

1 Mark(s)

reverse
none of the above
either forward or reverse
forward

The leakage current in a crystal diode is due to ___________

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minority carriers
majority carriers
none of the above
junction capacitance

The most widely used rectifier is ___________

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none of the above
bridge full-wave rectifier
half-wave rectifier
centre-tap full-wave rectifier

If the doping level in a crystal diode is increased, the width of depletion layer___________

1 Mark(s)

none of the above
is decreased
remains the same
in increased

An ideal crystal diode is one which behaves as a perfect ___________ when forward biased.

1 Mark(s)

none of the above
insulator
resistance material
conductor

If the doping level of a crystal diode is increased, the breakdown voltage___________

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is increased
is decreased
remains the same
none of the above

A zener diode is used as ___________

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a multivibrator
an amplifier
a rectifier
a voltage regulator

Mains a.c. power is converrted into d.c. power for ___________

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none of the above
lighting purposes
using in electronic equipment
heaters

The reverse current in a diode is of the order of ___________

1 Mark(s)

A
μA
kA
mA

A zener diode utilizes ___________ characteristics for its operation.

1 Mark(s)

reverse
both forward and reverse
forward
none of the above

A 10 V power supply would use ___________ as filter capacitor.

1 Mark(s)

paper capacitor
air capacitor
mica capacitor
electrolytic capacitor

The forward voltage drop across a silicon diode is about ___________

1 Mark(s)

3 V
10 V
2.5 V
0.7 V

The ripple factor of a half-wave rectifier is ___________

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2.5
0.48
2
1.21

A zener diode has ___________

1 Mark(s)

one pn junction
three pn junctions
none of the above
two pn junctions

If the temperature of a crystal diode increases, then leakage current ___________

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increases
becomes zero
decreases
remains the same

When the graph between current through and voltage across a device is a straight line, the device is referred to as ___________

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linear
nonlinear
passive
active

Semiconductor Diode Model Test(1st) : Question 1 of 44