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Unit – I:SINGLE STAGE AMPLIFIERS
ASSIGNMENT I
OBJECTIVE TYPE QUESTIONS
1. Which of the following amplifier has high power gain [ b]
(a) CB (b) CE (c) CC (d) both CB and CE
2. The slope of ac load line is _________ that of dc load line. [b ]
(a) same as (b)more than (c) less than (d) None of the above
3. In a RC coupled amplifier, which of the following component is mainly responsible for
harmonic distortion of the signal [ a]
(a) Transistor (b) Biasing resistor (c) coupling capacitor (d) power supply
4. The voltage gain of well designed single stage CB amplifier is essentially determined by
ac collector load and [C ]
A. Emitter resistor Re B. ac alpha C. Input resistance emitter diode D.ac beta.
5. The emitter of a CE amplifier has no AC voltage because of the [c ]
A. DC voltage unit B. Bypass Capacitor C. Coupling capacitor D. load resistance
FILL IN THE BLANKS
1. The parameter h22 has units of SEIMENS
2. A CC Amplifier has highest current gain but lowest power gain
3. The current gain of single stage CE amplifier is nearly equal to Beta
4. According to Miller’s theorem, the feedback capacitance when referred to input side with
gain A is _Cin = C(1-A)
5. The phase difference between output and input voltages of a CB amplifier is 0
Unit – I:SINGLE STAGE AMPLIFIERS
ASSIGNMENT II
Unit – II : BJT AMPLIFIERS - FREQUENCY RESPONSE
ASSIGNMENT I
OBJECTIVE TYPE QUESTIONS
1. The gain bandwidth product of a two stage amplifier is [ c ]
(a) same as that of single stage (b) greater than that of single stage
(c) less than that of single stage (d) product of two gain bandwidth products of each stage
2. How does the amplifier behave for high frequencies? [ b ]
(a) high pass filter (b) low pass filter (c) band pass filter (d) None
3. The bandwidth of an amplifier can be increased by [b ]
A. decreasing the capacitance of its bypass capacitors B.minimizing the stray capacitance
C.increasing the input signal frequency D. cascading it
4. Lower cutoff frequency of an amplifier is primarily determined by the [D ]
A.Internal capacitance of the active device
B.Stray capacitance between its wiring and ground
C.ac beta(β) value of its active devices
D.Capacitances of coupling and bypass capacitor
5. The main reason for the variation of amplifier gain with frequency is [A ]
A. the presence of capacitance internal and external B. due to interstage transformation
C. the logarithmic increase in its output power D. miller effect
FILL IN THE BLANKS
6. The alpha (α) cut off frequency of a transistor is higher than is beta (β) cut-off frequency
7. The alpha (α) of the transistor Decreases with the increase in frequency
Unit – III : MULTI STAGE AMPLIFIERS
ASSIGNMENT I
OBJECTIVE TYPE QUESTIONS
1. The most desirable feature of transformer coupling is its [c]
A. Higher voltage gain B. wide frequency range C.ability to provide impedance matching D.
ability to eliminate hum from the output
2. For matching a circuit of output impedance 200Ω with a load of 8 Ω the turn ratio of the
two winding transformer should be [d ]
A. 25 B.1/25 C.1/5 D.5
3. In the initial stages of a multi stage amplifier, we use [a ]
(a) RC coupling (b) transformer coupling (c) direct coupling (d) None
4. The bandwidth of a single stage amplifier is ___ that of a multi stage amplifier.
[ a]
(a) more than (b) less than (c) same as (d) none
5. The Darlington pair consists of the following two stages [ d ]
(a) CE,CC (b)CE,CB (c)both CE (d) both CC
FILL IN THE BLANKS
6. Transformer coupling is generally used when RL is Small
7. In a two stage cascaded amplifier, each of two cascaded stages has a voltage gain of 30
then the overall gain is _900
8. Why do we go for multi stage amplifiers? for high gain
9.Direct coupled amplifiers are especially suited for amplifying extremelyLOWfrequency
signals.
10. The DC resistance of transformer coupling is Low so it is more efficient
Unit – III : MULTI STAGE AMPLIFIERS
ASSIGNMENT II
1) Match List-I with List-II and select the correct answer using the codes given below
the lists:
List-I
List-II
A) Darlington amplifier
1.An output current is the same in
both the devices in the output
B)Cascade Connection
2.The output current of the first
device becomes the input current
of the second device.
C) Differential Amplifier
3.The collector of the first device
is connected to the base of the
second device without using a
capactor.
D) Direct coupled amplifier
4.output voltage depends on the
relative values of the two input
voltages
Codes:
A
B
C
D
a)
1
2
1
2
b)
2
1
2
1
c)
3
4
1
2
d)
4
3
2
1
Unit – IV: LARGE SIGNAL AMPLIFIERS
ASSIGNMENT I
OBJECTIVE TYPE QUESTIONS
1) Non-linear distortion is maximum in
a) class B mode
b) class A mode
c) class AB mode
d) class C mode
2) final stage of multistage amplifier is generally
a) apre-amplifier
b) a voltage post amplifier
c) a power amplifier
d) a microphone amplifier
3) Max conversion efficiency of a series fed class A power amplifier is
a) 75
b) 100
c) 50
d) 25
4) even harmonics are not present in the o/p of
a) class A transformer coupled amplifier
b) class c amplifier
c)class A amplifier
d) class B push pull amplifier
5) Even harmonics in the o/p are connected in push - pull configurations only if [ ]
a) both transistors are perfectly matched
b) both NPN & PNP transistors are used
c) A phase inversion is not used at inputs of 2 transistors
d) two power supplies are used
ans:[ A ]
FILL IN THE BLANKS
6) i/p signals swing in class A power amplifier is restricted to-------------ans: entire portion around Q point in active
7) transistor in class C amplifier is based beyond cutoff region to -----------------
ans: ensure conduction angle of less than 180 degrees
8) increased conversion efficiency in class B over class A operation is mainly due to---------------ans: elimination of dc current in the load
9. Non linear distortion is maximum in ------------------Ans: Class A mode
10) Cross over distortion in class B amplifier is due to-----------------
Unit – V: TUNED AMPLIFIERS
ASSIGNMENT I
OBJECTIVE TYPE QUESTIONS
1. A parallel tuned circuit is also known as
a. matched circuit b. notch circuit
c. resonant circuit
d. anti resonant circuit
2. What factors govern the selectivity of a single tuned amplifier ?
a. resonant frequency and gain
b. quality factor and bandwidth
c. quality factor and gain d. gain and bandwidth
3. The harmonic distortion of an ideal tuned amplifier is
a. unity
b. zero
c. infinity
d. depends on tuned circuit
4. Higher quality factor of a single tuned amplifier provides a
a. higher selectivity and bandwidth b. smaller selectivity and bandwidth
c. higher selectivity and smaller bandwidth
d. smaller selectivity and higher bandwidth
5. The function of tuned circuit in Tuned Amplifier is
a. allows only dc signal
b. reject dc and allow all frequencies
c. selecting a particular frequency and rejecting all other frequencies
d. passing all frequencies
FILL IN THE BLANKS
1. Tapping in the LC tuned circuit is used to --------2. The tapping point in a tapped single tuned capacitance coupled Amplifier divide the
inductance L into two part such that -------3. The gain bandwidth product of a single tuned capacitive couple amplifier is --------
4. The LC tuned circuit of single tuned capacitive coupled amplifier is not connected between
collector and ground because --------5. In a single tuned transformer coupled amplifier, the output is taken by ---------