Which of the following is not true: A) An oscillator is a circuit that converts DC to AC B) An oscillator is an amplifier that supplies its own input signal C) All oscillators generate sine waves D) In phase feedback is called positive Feedback

Which of the following is not true:
A) An oscillator is a circuit that converts DC to
AC
B) An oscillator is an amplifier that supplies its
own input signal
C) All oscillators generate sine waves
D) In phase feedback is called positive
Feedback
by

1 Answer

Answer :

C) All oscillators generate sine waves
by

Related questions

If the operating point of an NPN transistor amplifier is selected in saturation region, it is likely to result in A) Thermal runaway of transistor B) Clipping of output in the positive half of the input signal C) Need for high dc collector supply D) Clipping of output in the negative half of the input signal

Description : If the operating point of an NPN transistor amplifier is selected in saturation region, it is likely to result in A) Thermal runaway of transistor B) Clipping of output in the positive half of the ... for high dc collector supply D) Clipping of output in the negative half of the input signal

Last Answer : B) Clipping of output in the positive half of the input signal

The major function of transistor. Q2 is A) It provides voltage gain B) It provides the feedback signal C) It isolates the oscillator from loading effects D) It provides a phase shift.

Description : The major function of transistor. Q2 is A) It provides voltage gain B) It provides the feedback signal C) It isolates the oscillator from loading effects D) It provides a phase shift.

Last Answer : ) It provides a phase shift.

What conditions are required for an amplifier to oscillate A) There must be feedback B) The feedback must be in phase C) The gain must be greater than the loss D) All the above are regd.

Description : What conditions are required for an amplifier to oscillate A) There must be feedback B) The feedback must be in phase C) The gain must be greater than the loss D) All the above are regd.

Last Answer : B) The feedback must be in phase

Load regulation is a measure of a power supplies ability keep a constant output under conditions of changing A) Line voltage B) Current demand C) Temperature D) Oscillator frequency.

Description : Load regulation is a measure of a power supplies ability keep a constant output under conditions of changing A) Line voltage B) Current demand C) Temperature D) Oscillator frequency.

Last Answer : A) Line voltage

An FET has a gate source bias of 2 V. The ac input signal is ± 1.2 V. The class of operation is A) A B) B C) C D) AB

Description : An FET has a gate source bias of 2 V. The ac input signal is ± 1.2 V. The class of operation is A) A B) B C) C D) AB

Last Answer : D) AB

In a resistance loaded, RC coupled amplifier the dc component is blocked by A) Load resistance RL B) Coupling capacitor, CC C) RB D) The transistor.

Description : In a resistance loaded, RC coupled amplifier the dc component is blocked by A) Load resistance RL B) Coupling capacitor, CC C) RB D) The transistor.

Last Answer : B) Coupling capacitor, CC

Which of the following contributes to harmonics distortion in amplifiers? A) Positive feedback B) Presence of noise C) Defective active device D) Non linearity in active device.

Description : Which of the following contributes to harmonics distortion in amplifiers? A) Positive feedback B) Presence of noise C) Defective active device D) Non linearity in active device.

Last Answer : D) Non linearity in active device.

As compared to a CB amplifier, a CE amplifier has A) Lower current amplification B) Higher current amplification C) Higher input resistance. D) Both (B) & (C)

Description : As compared to a CB amplifier, a CE amplifier has A) Lower current amplification B) Higher current amplification C) Higher input resistance. D) Both (B) & (C)

Last Answer : D) Both (B) & (C)

The device which converts AC to DC is (1) Oscillator (2) Amplifier (3) Rectifier (4) None of these

Description : The device which converts AC to DC is (1) Oscillator (2) Amplifier (3) Rectifier (4) None of these

Last Answer : (3) Rectifier Explanation: A rectifier is an electrical device that converts alternating current (AC). which periodically reverses direction, to direct current (DC), which flows in only one ... serving as components of DC power supplies and high-voltage direct current power transmission systems.

The device which converts AC to DC is (1) Oscillator (2) Amplifier (3) Rectifier (4) None of these

Description : The device which converts AC to DC is (1) Oscillator (2) Amplifier (3) Rectifier (4) None of these

Last Answer : Rectifier

Which of the following methods cannot be used to increase the bandwidth for cascaded RF amplifier stages? A) Wave traps in each stage B) Stagger tuning C) A shunt damping resistor across each tuned circuit D) Doubled tuned transformers with tighter coupling

Description : Which of the following methods cannot be used to increase the bandwidth for cascaded RF amplifier stages? A) Wave traps in each stage B) Stagger tuning C) A shunt damping resistor across each tuned circuit D) Doubled tuned transformers with tighter coupling

Last Answer : A) Wave traps in each stage

Which of the following circuit would be preferred for a 455 kHz IF amplifier? A) A resistance loaded B) Double tuned transformer C) Video amplifier D) Class C

Description : Which of the following circuit would be preferred for a 455 kHz IF amplifier? A) A resistance loaded B) Double tuned transformer C) Video amplifier D) Class C

Last Answer : B) Double tuned transformer

Six (6) MHz crystal oscillator has a stability of 1 part in 106. The largest frequency error expected of this crystals A) 0.06 Hz B) 0.6 Hz C) 6 Hz D) 60 Hz.

Description : Six (6) MHz crystal oscillator has a stability of 1 part in 106. The largest frequency error expected of this crystals A) 0.06 Hz B) 0.6 Hz C) 6 Hz D) 60 Hz.

Last Answer : C) 6 Hz

An oscillator that uses crystal control should be A) Frequency stable B) useful only at low frequencies C) AVFO D) none of the above.

Description : An oscillator that uses crystal control should be A) Frequency stable B) useful only at low frequencies C) AVFO D) none of the above.

Last Answer : A) Frequency stable

Which of the following combinations has no phase inversion of the signal? A) Two CE stages B) CE and CC stages C) Three CE stages D) CE stage and emitter follower.

Description : Which of the following combinations has no phase inversion of the signal? A) Two CE stages B) CE and CC stages C) Three CE stages D) CE stage and emitter follower.

Last Answer : A) Two CE stages

What is the phase relationship of the signal at the collector of Q2 to the signal at the collector of Q, A) 0° B) 90° C) 180° D) 360°.

Description : What is the phase relationship of the signal at the collector of Q2 to the signal at the collector of Q, A) 0° B) 90° C) 180° D) 360°.

Last Answer : C) 180°

Current limited power supplies can prevent damage to A) Rectifier diodes and power transformers. B) Pass transistors C) Other circuits in the system D) All of the above.

Description : Current limited power supplies can prevent damage to A) Rectifier diodes and power transformers. B) Pass transistors C) Other circuits in the system D) All of the above.

Last Answer : D) All of the above.

In an amplifier if conductor during the cycle is from 0 to 90° and again from 180° to 270°, the amplifier will be termed as A) Class A B) Class B C) Class C D) Class AB.

Description : In an amplifier if conductor during the cycle is from 0 to 90° and again from 180° to 270°, the amplifier will be termed as A) Class A B) Class B C) Class C D) Class AB.

Last Answer : B) Class B

A push pull amplifier balances out A) Odd harmonics B) Even harmonics C) Both odd as well as even harmonics D) Neither odd nor even harmonics.

Description : A push pull amplifier balances out A) Odd harmonics B) Even harmonics C) Both odd as well as even harmonics D) Neither odd nor even harmonics.

Last Answer : A) Odd harmonics

Which amplifier will be preferred for highest gain? A) Darlington's pair B) Cascade amplifier C) Cascode amplifier D) Depends on the circuitry

Description : Which amplifier will be preferred for highest gain? A) Darlington's pair B) Cascade amplifier C) Cascode amplifier D) Depends on the circuitry

Last Answer : C) Cascode amplifier

In an amplifier the collector voltage equals the full V+ of 28 V instead of the normal 12 V which of the following can be the trouble? A) RL is open B) Cc is open C) RE is open D) CE is shorted.

Description : In an amplifier the collector voltage equals the full V+ of 28 V instead of the normal 12 V which of the following can be the trouble? A) RL is open B) Cc is open C) RE is open D) CE is shorted.

Last Answer : B) Cc is open

In a resistance loaded amplifier, the gain decreases a high frequencies because A) Of decreasing reactance of the stray CT B) Increasing reactance of the stray CT C) Increasing reactance of CC D) Decreasing reactance of CC.

Description : In a resistance loaded amplifier, the gain decreases a high frequencies because A) Of decreasing reactance of the stray CT B) Increasing reactance of the stray CT C) Increasing reactance of CC D) Decreasing reactance of CC.

Last Answer : D) Decreasing reactance of CC.

An ideal voltage amplifier should have A) Ri = 0, R0 = 0 B) Ri = 0, R0 =∞ C) Ri = ∞, R0 = 0 D) Ri = ∞, R0 = ∞.

Description : An ideal voltage amplifier should have A) Ri = 0, R0 = 0 B) Ri = 0, R0 =∞ C) Ri = ∞, R0 = 0 D) Ri = ∞, R0 = ∞.

Last Answer : C) Ri = ∞, R0 = 0

The Bandwidth of an RC-coupled amplifier is limited by: A) coupling capacitors at the low frequency end and bypass capacitors at the high frequency end B) coupling capacitors at the high frequency end and bypass capacitors at the low frequency end C) bypass and coupling capacitors at the low frequency end and shunt capacitors at the high frequency end and D) shunt capacitors at the low frequency end and bypass as well as coupling capacitors at the high frequency end.

Description : The Bandwidth of an RC-coupled amplifier is limited by: A) coupling capacitors at the low frequency end and bypass capacitors at the high frequency end B) coupling capacitors at the high frequency ... at the low frequency end and bypass as well as coupling capacitors at the high frequency end.

Last Answer : C) bypass and coupling capacitors at the low frequency end and shunt capacitors at the high frequency end and

Common base configuration is little used because A) It has low input impedance B) It has high input impedance C) It does not heat up D) It has very high gain.

Description : Common base configuration is little used because A) It has low input impedance B) It has high input impedance C) It does not heat up D) It has very high gain.

Last Answer : A) It has low input impedance

Positive feedback is used in 1. Amplifier 2. Rectifier 3.Oscillator 4. Detector

Description : Positive feedback is used in 1. Amplifier 2. Rectifier 3.Oscillator 4. Detector 

Last Answer : Positive feedback is used in 1. Amplifier 2. Rectifier 3.Oscillator 4. Detector 

Which distortion is least objectionable in case of audio amplifers? A) Phase distortion B) Frequency distortion C) Harmonic distortion D) Inter modulation distortion.

Description : Which distortion is least objectionable in case of audio amplifers? A) Phase distortion B) Frequency distortion C) Harmonic distortion D) Inter modulation distortion.

Last Answer : A) Phase distortion

A series mode crystal is marked 10.000 MHz., It is used in a circuit that operates the crystal in its parallel mode. The circuit can be expected to A) Run below 10 MHz B) Run at 10 MHz C) Run above 10 MHz D) Not oscillate.

Description : A series mode crystal is marked 10.000 MHz., It is used in a circuit that operates the crystal in its parallel mode. The circuit can be expected to A) Run below 10 MHz B) Run at 10 MHz C) Run above 10 MHz D) Not oscillate.

Last Answer : C) Run above 10 MHz

Foldback current limiting has the advantage of A) Better pass transistor protection for long term overloads B) A defined turn on point C) Circuit simplicity D) All of the above.

Description : Foldback current limiting has the advantage of A) Better pass transistor protection for long term overloads B) A defined turn on point C) Circuit simplicity D) All of the above.

Last Answer : A) Better pass transistor protection for long term overloads

A crow bar is a power supply circuit that provides A) Conventional current limiting B) Foldback current. limiting C) Temperature control D) Voltage limiting.

Description : A crow bar is a power supply circuit that provides A) Conventional current limiting B) Foldback current. limiting C) Temperature control D) Voltage limiting.

Last Answer : D) Voltage limiting.

In the inverting configuration, what is the voltage (for all practical purposes) at the inverting input to the operational amplifier if the input signal is a 1-volt, peak-to-peak sine wave?

Description : In the inverting configuration, what is the voltage (for all practical purposes) at the inverting input to the operational amplifier if the input signal is a 1-volt, peak-to-peak sine wave?

Last Answer : 0 volts.

One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency oscillation. A. Heating and expansion of oscillator coil B. DC and RF ac heating of resistors which cause change in values C. Heating of capacitor in the oscillatorD. Loose connections in the oscillator, amplifier, or antenna circuits.

Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.

Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.

Which components provide the regenerative feedback signal in the phase-shift oscillator?

Description : Which components provide the regenerative feedback signal in the phase-shift oscillator?

Last Answer : Resistor-capacitor networks.

A transformer in an electric circuit serves to ____________. A. generate its own electrical power B. transform electrical energy into mechanical energy C. increase or decrease circuit voltage as required D. convert AC current to DC current

Description : A transformer in an electric circuit serves to ____________. A. generate its own electrical power B. transform electrical energy into mechanical energy C. increase or decrease circuit voltage as required D. convert AC current to DC current

Last Answer : Answer: C

Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will

Description : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will   (A) Amplify the noise as much as the signal (B) Reduce the noise (C) Increase the noise (D) Not effect the noise

Last Answer : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will Reduce the noise

The circuit which changes input signal at output with phase shift of 1800 is called (a) Amplifier (b) operational amplifier (c) switch (d) inverter

Description : The circuit which changes input signal at output with phase shift of 1800 is called (a) Amplifier (b) operational amplifier (c) switch (d) inverter

Last Answer : (d) inverter

The change in base current will be A) 0.66 micro ampere B) 6.6 micro amperes C) 66 micro amperes D) 660 micro amperes.

Description : The change in base current will be A) 0.66 micro ampere B) 6.6 micro amperes C) 66 micro amperes D) 660 micro amperes.

Last Answer : A) 0.66 micro ampere

A IGFET is a A) Linear device B) Square law device C) Half power device D) 3/2 power law device.

Description : A IGFET is a A) Linear device B) Square law device C) Half power device D) 3/2 power law device.

Last Answer : B) Square law device

The Darlington pair consists of the following two stages A) CE and CC B) Both C) Both CC D) CE and CB

Description : The Darlington pair consists of the following two stages A) CE and CC B) Both C) Both CC D) CE and CB

Last Answer : C) Both CC

In general, MOV devices are used to protect electronic equipment from dangerous operating conditions such as A) High temperatures B) Line transients C) Over current D) All of the above.

Description : In general, MOV devices are used to protect electronic equipment from dangerous operating conditions such as A) High temperatures B) Line transients C) Over current D) All of the above.

Last Answer : D) All of the above.

The ideal characteristic of a voltage stablizer is A) constant output voltage with low internal resistance B) constant output current with low internal resistance C) constant output voltage with high internal resistance D) constant internal resistance with variable output voltage.

Description : The ideal characteristic of a voltage stablizer is A) constant output voltage with low internal resistance B) constant output current with low internal resistance C) constant output voltage with high internal resistance D) constant internal resistance with variable output voltage.

Last Answer : A) constant output voltage with low internal resistance

Basic operating characteristics of the operational amplifier such as gain and stability are the function of its _____________. A. differential input stage B. power output stage C. feedback circuit D. supply voltages

Description : Basic operating characteristics of the operational amplifier such as gain and stability are the function of its _____________. A. differential input stage B. power output stage C. feedback circuit D. supply voltages

Last Answer : Answer: C

The conversion of the throttle command voltage to the signal necessary to achieve the desired shaft RPM is accomplished by the _____________. A. ahead or astern function generator of the throttle control circuit B. feedback resistor of the summing amplifier circuit C. operational amplifiers in the autorotation circuit D. long time constant amplifier circuit

Description : The conversion of the throttle command voltage to the signal necessary to achieve the desired shaft RPM is accomplished by the _____________. A. ahead or astern function generator of the ... circuit C. operational amplifiers in the autorotation circuit D. long time constant amplifier circuit

Last Answer : Answer: A

AC and DC generators are similar in that they _____________. A. both generate alternating voltages B. both rectify the voltage before delivery C. are constructed at the same physical size for the same kilowatt rating D. both supply three-phase power

Description : AC and DC generators are similar in that they _____________. A. both generate alternating voltages B. both rectify the voltage before delivery C. are constructed at the same physical size for the same kilowatt rating D. both supply three-phase power

Last Answer : Answer: A

Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections B. Power supply voltage changes C. Loose connections in the oscillator, amplifier, or antenna circuits D. DC and RF heating of resistors, causing then to change values.

Description : Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections ... , or antenna circuits D. DC and RF heating of resistors, causing then to change values.

Last Answer : D. DC and RF heating of resistors, causing then to change values.

One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the high power output. The purpose of which is to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley

Description : One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the ... to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley

Last Answer : B. MOPA

In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal from the resistor at the top of the speed sensing circuit card C. hall effect current to detect slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Description : In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal ... slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Last Answer : Answer: A

Referred to an oscillator signal “leak through” from a properly neutralized amplifier such as a master oscillator power amplifier. A. Carrier B. Stray signal C. Back wave D. Loss wave

Description : Referred to an oscillator signal “leak through” from a properly neutralized amplifier such as a master oscillator power amplifier. A. Carrier B. Stray signal C. Back wave D. Loss wave

Last Answer : C. Back wave

What are three advantages of adding an ac bias voltage to the input signal instead of adding a fixed dc bias voltage?

Description : What are three advantages of adding an ac bias voltage to the input signal instead of adding a fixed dc bias voltage?

Last Answer : a. Reproduces a stronger output signal. b. Greatly improves the SNR. c. Greatly reduces the natural tape hiss.

Why does adding dc vice ac bias voltage to the input signal result in a poor signal-to-noise ratio (SNR)?

Description : Why does adding dc vice ac bias voltage to the input signal result in a poor signal-to-noise ratio (SNR)?

Last Answer : With dc bias, the SNR is poor because only a small portion of the magnetism curve is straight enough to use, thus the output signal is weak compared with the natural tape hiss.