1 $An ideal Voltage Amplifier is characterized by which of the following input () and output () resistance values?$

A.

B.

C.

D.

2 $What is the mathematical expression for the gain with negative feedback (), given open-loop gain and feedback factor ?$

A.

B.

C.

D.

3 $The quantity in a negative feedback amplifier is known as:$

A.

Loop Gain

B.

Return Ratio

C.

Amount of Feedback (Desensitivity)

D.

Feedback Factor

4 $If the feedback signal is proportional to the output voltage and is mixed in series with the input signal, the topology is classified as:$

A.

Current-Series Feedback

B.

Voltage-Shunt Feedback

C.

Current-Shunt Feedback

D.

Voltage-Series Feedback

5 $Negative feedback in an amplifier generally results in which of the following changes to bandwidth?$

A.

Bandwidth decreases

B.

Bandwidth remains unchanged

C.

Bandwidth increases

D.

Bandwidth becomes zero

6 $Which feedback topology is used to convert a Transconductance Amplifier into a stable amplifier?$

A.

Voltage-Series

B.

Current-Series

C.

Voltage-Shunt

D.

Current-Shunt

7 $In a Voltage-Series feedback amplifier, what is the effect on input resistance () and output resistance ()?$

A.

increases, increases

B.

decreases, decreases

C.

increases, decreases

D.

decreases, increases

8 $Calculate the percentage change in closed-loop gain if the open-loop gain changes by 10%, given and .$

A.

10%

B.

1%

C.

0.1%

D.

5%

9 $Which feedback topology corresponds to a Current Amplifier ?$

A.

Voltage-Series

B.

Voltage-Shunt

C.

Current-Series

D.

Current-Shunt

10 $In Current-Series feedback, the feedback signal is proportional to the output current and is:$

A.

A voltage fed in series with the input

B.

A current fed in shunt with the input

C.

A voltage fed in shunt with the input

D.

A current fed in series with the input

11 $What is the unit of the feedback factor in a Transresistance (Voltage-Shunt) amplifier?$

A.

Ohms ()

B.

Siemens (S) or Mho

C.

Dimensionless

D.

Volts

12 $Identify the topology of an Emitter Follower (Common Collector) amplifier circuit.$

A.

Voltage-Series Feedback

B.

Current-Series Feedback

C.

Voltage-Shunt Feedback

D.

Current-Shunt Feedback

13 $How does negative feedback affect non-linear distortion ()?$

A.

B.

C.

D.

14 $In a Voltage-Shunt feedback amplifier, the input resistance () and output resistance () change as follows:$

A.

increases, increases

B.

decreases, decreases

C.

increases, decreases

D.

decreases, increases

15 $The 'Miller Effect' in the high-frequency response of an amplifier refers to:$

A.

The increase in output resistance due to feedback

B.

The reduction of gain at low frequencies

C.

The multiplication of the feedback capacitance at the input

D.

The thermal noise generation in resistors

16 $For a Current-Shunt feedback amplifier, the output resistance is given by (where is open loop output resistance):$

A.

B.

C.

D.

17 $The low-frequency response of an RC-coupled amplifier is primarily limited by:$

A.

Inter-electrode capacitances

B.

Coupling and bypass capacitors

C.

Wiring inductance

D.

Transit time of charge carriers

18 $If an amplifier has a lower cutoff frequency Hz, what will be the new lower cutoff frequency with negative feedback if ?$

A.

1000 Hz

B.

100 Hz

C.

10 Hz

D.

1 Hz

19 $Which component in the high-frequency model of a FET is primarily responsible for the dominant pole (limiting high-frequency response)?$

A.

Source bypass capacitor

B.

Gate-Drain capacitance ()

C.

Coupling capacitor

D.

Load resistor

20 $The stability of an amplifier with feedback is ensured if the loop gain satisfies which condition according to the Nyquist criterion (simplified)?$

A.

B.

when phase shift is

C.

D.

Phase shift is

21 $A Common Emitter amplifier with an unbypassed Emitter resistor () represents which feedback topology?$

A.

Current-Series

B.

Voltage-Series

C.

Current-Shunt

D.

Voltage-Shunt

22 $The reduction in gain due to negative feedback is often expressed in decibels () as:$

A.

B.

C.

D.

23 $In a voltage series feedback amplifier, if the open loop gain and, calculate the closed loop gain .$

A.

9.09

B.

-9.09

C.

-10

D.

100

24 $At the cut-off frequencies ( and ), the gain of the amplifier drops to what fraction of the mid-band gain?$

A.

B.

C.

$0.9$

D.

25 $The rate of fall of gain in the low-frequency region of a single stage RC coupled amplifier is:$

A.

6 dB/decade

B.

20 dB/decade

C.

40 dB/decade

D.

10 dB/decade

26 $Ideally, a Current-Series feedback amplifier approaches the characteristics of an ideal:$

A.

Voltage Amplifier

B.

Current Amplifier

C.

Transconductance Amplifier

D.

Transresistance Amplifier

27 $The phenomenon where the top of a square wave input tilts in the output of an RC coupled amplifier is called 'Sag' or 'Tilt'. This is caused by:$

A.

Poor high-frequency response

B.

Poor low-frequency response

C.

Non-linear distortion

D.

Miller effect

28 $What is the unit of for a Voltage-Series feedback amplifier?$

A.

Ohms

B.

Siemens

C.

Unitless (Volt/Volt)

D.

Amperes

29 $Ideally, a Voltage-Shunt feedback amplifier approaches the characteristics of an ideal:$

A.

Voltage Amplifier

B.

Current Amplifier

C.

Transresistance Amplifier

D.

Transconductance Amplifier

30 $Frequency distortion in an amplifier occurs when:$

A.

The amplifier is non-linear

B.

Different frequency components are amplified by different amounts

C.

There is a phase shift proportional to frequency

D.

Noise is added to the signal

31 $In the high-frequency region, the gain of an amplifier decreases due to:$

A.

Coupling capacitors

B.

Bypass capacitors

C.

Device internal capacitances and stray capacitances

D.

Power supply ripple

32 $Which of the following defines the Gain-Bandwidth Product ()?$

A.

B.

C.

D.

33 $For a Current-Shunt feedback network, the feedback factor relates:$

A.

Feedback voltage to Output voltage

B.

Feedback current to Output current

C.

Feedback voltage to Output current

D.

Feedback current to Output voltage

34 $If an amplifier has a bandwidth of 200 kHz and a gain of 100, and negative feedback reduces the gain to 20, what is the new bandwidth?$

A.

200 kHz

B.

1 MHz

C.

40 kHz

D.

10 MHz

35 $The phase shift introduced by the internal amplifier circuit in a negative feedback system should ideally be:$

A.

or

B.

C.

D.

36 $The input impedance of a FET at low frequencies is extremely high because:$

A.

The gate is reverse biased (JFET) or insulated (MOSFET)

B.

The Miller effect is zero

C.

It uses current series feedback

D.

The drain current is zero

37 $The transition frequency of a transistor is the frequency at which:$

A.

The current gain drops to unity (1)

B.

The voltage gain drops to unity (1)

C.

The power gain is maximum

D.

The beta value becomes zero

38 $In a FET amplifier high-frequency analysis, (Input capacitance) is defined as:$

A.

B.

C.

D.

39 $Negative feedback reduces noise in an amplifier only if:$

A.

The noise is generated at the input

B.

The noise is generated within the amplifier stages preceded by high gain

C.

The feedback factor is 1

D.

The amplifier is a vacuum tube

40 $The Voltage-Shunt feedback topology is also known as:$

A.

Series-Series Feedback

B.

Shunt-Series Feedback

C.

Shunt-Shunt Feedback

D.

Series-Shunt Feedback

41 $Formula for the percent tilt () in a square wave response due to low frequency cutoff and square wave frequency :$

A.

B.

C.

D.

42 $Which resistor defines the feedback path in a standard inverting Op-Amp circuit (Voltage-Shunt topology)?$

A.

The resistor connected from Output to Ground

B.

The resistor connected from Output to Inverting Input

C.

The resistor connected from Output to Non-Inverting Input

D.

The input source resistor

43 $In a multistage amplifier, if individual stages have bandwidths and, the overall bandwidth is:$

A.

Greater than the largest individual bandwidth

B.

Equal to the sum of bandwidths

C.

Less than the smallest individual bandwidth

D.

Equal to the average

44 $A feedback amplifier has an open loop gain . If 10% of the output is fed back negatively, the closed loop gain is approximately:$

A.

100

B.

10

C.

9.9

D.

1

45 $The relationship between Rise Time () and Bandwidth () (upper cutoff frequency) is roughly:$

A.

B.

C.

D.

46 $Why is the gain of an RC coupled amplifier low at very low frequencies?$

A.

Because reactance of coupling capacitors increases

B.

Because reactance of coupling capacitors decreases

C.

Because transistor beta decreases

D.

Because of Miller effect

47 $What happens to the input resistance in a Current-Shunt feedback amplifier?$

A.

Increases

B.

Decreases

C.

Remains same

D.

Becomes infinite

48 $Which of the following describes the output connection for Voltage sampling?$

A.

Feedback network connected in Series with the load

B.

Feedback network connected in Parallel with the load

C.

Feedback network connected directly to ground

D.

Feedback network open circuited

49 $A Source Follower (Common Drain) FET amplifier utilizes which type of feedback?$

A.

Voltage-Series

B.

Current-Series

C.

Voltage-Shunt

D.

Current-Shunt

50 $If the feedback signal is derived from the output current and mixed in shunt with the input, the topology is:$

A.

Current-Shunt

B.

Current-Series

C.

Voltage-Shunt

D.

Voltage-Series

Unit 1 - Practice Quiz