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WorksheetsAnalog Circuits
Total questions: 20
Worksheet time: 10mins
The break down voltage of a transistor with its base open is BVCEO and that with emitter open is BVCBO, then
BVCEO = BVCBO
BVCEO > BVCBO
BVCEO < BVCBO
BVCEO is not related to BVCBO
A BJT is said to be operating in the saturation region if
(a)
Both junctions are reverse biased
Base – emitter junction is reverse biased and base collector junction is forward biased
Base – emitter junction is forward biased and base – collector junction reverse biased
Both the junctions are forward biased
The Ebers – Moll model is applicable to
Bipolar junction transistors
NMOS transistors
Unipolar junction transistors
Junction field – effect transistors
The Early – Effect in a bipolar junction transistor is caused by
Fast – turn – on.
Fast – turn – off.
Large collector – base reverse bias.
Large emitter – base forward bias.
If for Si n – p – n transistor, the base to emitter voltage (𝑉𝐵𝐸 ) is 0.7V and
collector to base voltage (𝑉𝐶𝐵 ) is 0.2V then the transistor is operating in the
Normal active mode
Saturation mode
Inverse active mode
Cut – off mode
Consider the following statements S1 and S2
S1: The β of a bipolar transistor reduces if the base width is increased.
S2: The β of a bipolar transistor increases if the doping concentration in the base is increased.
Which one of the following is correct?
S1 is FLASE and S2 is TRUE
Both S1 and S2 are TRUE
Both S1 and S2 are FLASE
S1 TRUE and S2 is FALSE
If the base width in a bipolar junction transistor is doubled, which one of
the following statements will be TRUE?
(a)
Current gain will increase
Unity gain frequency will increase.
Emitter – base junction capacitance will increase.
Early voltage will increase
In a bipolar – transistor at room temperature, if the emitter current is doubled, the voltage across its base – emitter junction
Doubles
Halves
Increases by about 20 mV
Decreases by about 20 mV
In a properly Biased NPN transistor most of the electrons from the emitter
recombine with holes in the base
recombine in the emitter its self
pass through the base to the collector
are stopped by the junction barrier
The CE amplifier circuit are preferred over CB amplifier circuit because they have
lower amplification factor
larger amplification factor
high input resistance and low output resistance
none of these
The dc load line of transistor circuit
is a graph between IC and VCE
is a graph between IC and IB
does not contain the Q Point
is a curved line
The ac load line of a transistor circuit is steeper than its dc line because
ac signal sees less load resistance
IC is higher
input signal varies in magnitude
none of the above
The maximum peak to peak output voltage swing is obtained when Q point of a circuit is located
near saturation point
near cutoff point
at the center of the load line
atleast on the load line
The positive part of the output signal in a transistor circuit starts clipping, if Q point of the circuit moves
toward the saturation point
toward the cutoff point
toward the center of the load line
none of the above
The biasing circuit that gives best stability to Q point is
base resistance biasing
feedback resistor biasing
potential divider biasing
emitter resistor biasing
The potential divider biasing is used in amplifiers to
limit the input ac signal going to the base
reduce dc base current
reduce the cost of the circuit by limiting the number of resistors
make the operating point almost independent of β
The ideal value of stability factor of a biasing circuit is
1
5
10
100
The cascode amplifier is a multistage configuration of
CC-CB
CE-CB
CB-CC
CE-CC
Generally, the gain of a transistor amplifier falls at high frequency due to the
Internal capacitance of the device
Coupling capacitor at the input
Skin effect
Coupling capacitor at the output
Match the following
(a) Cascode amplifier
(b) Differential amplifier
(c) Darlington pair common-collector amplifier
Amplifier
(1) Does not provide current gain
(2) Is a wide band amplifier
(3) Has very high input impedance and very high current gain
(4) Provides high common mode voltage rejection
a-2, b-4, c-3
a-1,b-2,c-3
a-3,b-1,c-2
a-4,b-3,c-1
