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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

101.

What is the role of the intensity section in a CRO?(a) decreases the light intensity(b) controls light intensity(c) increases the light intensity(d) keeps the light intensity zeroThis question was posed to me in an interview.This key question is from Front Panel Controls of CRO in chapter Oscilloscopes of Electrical Measurements

Answer»

Right option is (B) CONTROLS light intensity

To elaborate: In a Cathode RAY Oscilloscope the intensity section controls the BRIGHTNESS or intensity of the light beam produced by the bombardment of ELECTRONS on the fluorescent screen.

102.

Front panel of a CRO has _________(a) 4 sections(b) 8 sections(c) 15 sections(d) 20 sectionsI got this question during an interview for a job.My question is based upon Front Panel Controls of CRO topic in chapter Oscilloscopes of Electrical Measurements

Answer»

The correct answer is (a) 4 SECTIONS

To elaborate: A simple Cathode RAY Oscilloscope has the following FOUR sections:

i) BASIC controls

ii) Vertical section

iii) Horizontal section

iv) Z axis intensity control.

103.

What is the effect of the signal delay on the sweep generator?(a) no effect(b) input increases in magnitude(c) output doesn’t get any delay(d) output gets sufficient delayThe question was posed to me in an online quiz.I want to ask this question from Delay Line in division Oscilloscopes of Electrical Measurements

Answer»

The correct answer is (d) OUTPUT gets sufficient delay

For explanation: When the signal is delayed, the sweep generator’s output gets sufficient time in order to reach the horizontal PLATES before the signal PASSES over to the VERTICAL DEFLECTION plates.

104.

Typical values for a distributed parameter delay line are ________(a) Zo = 10 Mῼ and td = 10 nsec/m(b) Zo = 1 kῼ and td = 500 nsec/m(c) Zo = 1000 ῼ and td = 180 nsec/m(d) Zo = 100 Gῼ and td = 275 nsec/mThis question was addressed to me in an interview for internship.I need to ask this question from Delay Line in portion Oscilloscopes of Electrical Measurements

Answer»

Right option is (c) Zo = 1000 ῼ and td = 180 nsec/m

Best explanation: For the distributed parameter DELAY line in a delay line CIRCUIT the typical PARAMETERS are the CHARACTERISTIC impedance which is Zo = 1000 ῼ and the delay time which is td = 180 nsec/m.

105.

Inductance does not affect a transmission line.(a) True(b) FalseThis question was posed to me in an online quiz.The above asked question is from Delay Line in chapter Oscilloscopes of Electrical Measurements

Answer»

Right choice is (B) False

The explanation is: The inductance of the TRANSMISSION line in a distributed parameter delay line can be increased by winding the INNER conductor of the helix onto a ferromagnetic core.

106.

Distributed parameter delay line is a transmission line.(a) True(b) FalseI have been asked this question during an interview.I need to ask this question from Delay Line in section Oscilloscopes of Electrical Measurements

Answer»

The CORRECT CHOICE is (a) True

The BEST explanation: The DELAY line circuit consists of distributed parameter delay as well as lumped parameter delay. The distributed parameter delay is basically a transmission line with a coil wound on a helix mandrel.

107.

Delay for the T section is given by ________(a) ts = ^1⁄fc(b) ts = 1(c) ts = ^1⁄π(d) ts = ^1⁄πfcThis question was posed to me in unit test.This interesting question is from Delay Line topic in division Oscilloscopes of Electrical Measurements

Answer»

Right choice is (d) ts = ^1⁄πfc

The explanation: In the T SECTION of the lumped parameter DELAY in a delay line CIRCUIT of the CRO the delay is GIVEN by the relation

ts = ^1⁄πfc

ts = delay for a single circuit

td = TOTAL delay

n = number of T sections.

108.

Lumped parameter delay line consists of________(a) RC networks(b) RL networks(c) LC networks(d) Resistive networksThis question was posed to me in unit test.This intriguing question originated from Delay Line in portion Oscilloscopes of Electrical Measurements

Answer»

The CORRECT option is (c) LC NETWORKS

For explanation: In the delay line circuit of a Cathode Ray Oscilloscope, the lumped parameter delay line is MADE of SEVERAL cascaded LC networks. They are KNOWN as T sections.

109.

T section in a delay circuit of CRO acts as ________(a) high pass filter(b) low pass filter(c) band pass filter(d) band reject filterThe question was asked in an online quiz.The query is from Delay Line topic in portion Oscilloscopes of Electrical Measurements

Answer»

Correct choice is (b) low pass FILTER

Best explanation: In the delay circuit of a CRO, T SECTION is present in the lumped parameter delay LINE. The T section acts as a low pass filter having a CUT off frequency as,

.

110.

CRO uses __________(a) 2 delay lines(b) 3 delay lines(c) 4 delay lines(d) 5 delay linesThe question was posed to me during an interview.My doubt stems from Delay Line topic in portion Oscilloscopes of Electrical Measurements

Answer»

Correct choice is (a) 2 delay lines

The best I can explain: Cathode Ray Oscilloscope USES TWO delay lines. They are as follows:

 LUMPED parameter delay LINE and

 DISTRIBUTED parameter delay line.

111.

Why is a delay line used in a CRO?(a) to boost the signal(b) to distort the signal(c) to provide signal delay(d) for stabilityThe question was posed to me in a job interview.This question is from Simple Oscilloscope in section Oscilloscopes of Electrical Measurements

Answer»

Correct CHOICE is (C) to provide signal delay

The explanation: Delay LINE is USED in a Cathode Ray Oscilloscope so as to delay the signal for some time. If the delay line is not used then a part of the signal is lost. A delay line circuit is used for this PURPOSE.

112.

BJT is used in the amplifier stage.(a) True(b) FalseThis question was posed to me by my school principal while I was bunking the class.The query is from Simple Oscilloscope in division Oscilloscopes of Electrical Measurements

Answer» RIGHT answer is (a) True

Explanation: A BJT emitter FOLLOWER is used in the AMPLIFIER stage after the FET in order to provide impedance matching to the output of the FET. With RESPECT to the INPUT of the phase-inverter.
113.

Phase inverter is used in an amplifier in the CRO because ___________(a) phase inversion is needed(b) no phase inversion is needed(c) it is needed to operate a push pull(d) it provides voltage stabilityThe question was posed to me in a national level competition.This key question is from Simple Oscilloscope in section Oscilloscopes of Electrical Measurements

Answer»

Right answer is (c) it is needed to operate a push pull

The explanation: In a CATHODE Ray Oscilloscope, phase inverter is typically used for operating a push pull AMPLIFIER. It provides TWO antiphase output signals in order to operate the push pull amplifier.

114.

Input stage in the amplifier consists of ___________(a) oscillator(b) attenuator(c) rectifier(d) op ampThis question was addressed to me in exam.My question is based upon Simple Oscilloscope topic in section Oscilloscopes of Electrical Measurements

Answer»

Right ANSWER is (b) attenuator

The best I can explain: The amplifier STAGE of a Cathode Ray Tube ESSENTIALLY consists of an attenuator stage. It is followed by a FET source FOLLOWER. The input impedance is very high.

115.

Amplifier is multiple stage in a CRO.(a) True(b) FalseThe question was asked during an interview.The origin of the question is Simple Oscilloscope in division Oscilloscopes of Electrical Measurements

Answer»

Right choice is (a) True

To explain I WOULD say: A Cathode Ray Tube essentially consists of MULTIPLE STAGES of amplifiers with a overall fixed sensitivity. Amplifier is designed for stability and required BANDWIDTH very easily due to the fixed GAIN.

116.

Role of an attenuator is ___________(a) to boost the signal(b) to distort the signal(c) to remove noise(d) to improve the operationI got this question during a job interview.Question is taken from Simple Oscilloscope topic in section Oscilloscopes of Electrical Measurements

Answer» CORRECT choice is (d) to IMPROVE the operation

The explanation: When we need to MEASURE very high VOLTAGE signals, attenuator stages are used. This is done in order to bring the signal LEVEL within the range of operation of the amplifier.
117.

Amplifier stage is ___________(a) half band(b) full band(c) wide band(d) narrow bandThis question was posed to me in an interview for job.I would like to ask this question from Simple Oscilloscope in section Oscilloscopes of Electrical Measurements

Answer»

Right OPTION is (c) wide band

For explanation I would say: Wide band amplifiers are generally USED to amplify the input signals. The whole band of FREQUENCY to be measured must be PASSED faithfully by making use of a wide band amplifier.

118.

Input signals are amplified using ___________(a) rectifier(b) amplifier(c) oscillator(d) op ampI have been asked this question in my homework.I'd like to ask this question from Simple Oscilloscope topic in division Oscilloscopes of Electrical Measurements

Answer»

Right answer is (b) AMPLIFIER

For explanation I would say: Vertical amplifier is used in a cathode ray tube to AMPLIFY the INPUT signals. MAGNITUDE of the input signal is weak and not sufficient enough to give DEFLECTION on the screen.

119.

What is the role of CRT?(a) to emit electrons(b) to emit protons(c) to emit neutrons(d) to emit alpha particlesThe question was asked during a job interview.This interesting question is from Simple Oscilloscope in portion Oscilloscopes of Electrical Measurements

Answer»

The correct option is (a) to emit electrons

The explanation: Cathode ray TUBE forms the heart of a C.R.O. It is USED to emit electrons so as to STRIKE the phosphor screen to produce a SPOT for the visual display of the signals.

120.

Light produced in a screen is _______(a) disappears immediately(b) does not disappear at all(c) is not visible to the eye(d) disappears slowlyI had been asked this question by my college professor while I was bunking the class.This key question is from Basic Principle of Signal Display topic in chapter Oscilloscopes of Electrical Measurements

Answer» CORRECT choice is (d) disappears SLOWLY

Easy explanation: When the magnitude of the applied voltage reduces to zero, the light produced on the screen DUE to the bombardment of electrons does not disappear IMMEDIATELY and reduces in terms of intensity slowly.
121.

During trace time, voltage is decreasing with time.(a) True(b) FalseI got this question in final exam.The origin of the question is Basic Principle of Signal Display topic in chapter Oscilloscopes of Electrical Measurements

Answer»

The correct answer is (b) False

The best I can EXPLAIN: The electron beam MOVES linearly along the horizontal direction during the trace time. The voltage Vx increases linearly with respect to time Tr during the INSTANT of the trace PERIOD.

122.

What is the flyback period?(a) voltage is very high(b) current is very low(c) voltage is zero(d) current is very highI got this question during a job interview.Enquiry is from Basic Principle of Signal Display topic in section Oscilloscopes of Electrical Measurements

Answer»

Right ANSWER is (c) voltage is zero

Best EXPLANATION: During the flyback period, voltage suddenly DROPS to zero from a certain value.

123.

Sinusoidal voltage is not observed on the screen.(a) True(b) FalseThe question was posed to me at a job interview.Question is from Basic Principle of Signal Display topic in chapter Oscilloscopes of Electrical Measurements

Answer»

Correct OPTION is (B) False

Explanation: Application of a sinusoidal voltage to the y terminal and the INTERNALLY produced sawtooth voltage to the x terminal RESULTS in the shifting of the sawtooth voltage in terms of magnitude. Finally a sinusoidal waveform is observed on the screen.

124.

A single cycle appears on the screen when _______(a) sweep and signal frequencies are equal(b) sweep and signal frequencies are not equal(c) sweep and signal frequencies are zero(d) sweep frequency is greater than signal frequencyThe question was asked by my school principal while I was bunking the class.The query is from Basic Principle of Signal Display in chapter Oscilloscopes of Electrical Measurements

Answer»

Correct CHOICE is (a) sweep and signal frequencies are equal

The best I can explain: Many CYCLES are PRESENT on the screen when the sweep FREQUENCY is lower than the signal frequency. Only a single cycle appears on the screen when the sweep and signal frequencies are equal.

125.

What is done to make the trace horizontal?(a) negative voltage is applied(b) positive voltage is applied(c) no voltage is applied(d) voltage is synchronisedThis question was posed to me during an interview for a job.This is a very interesting question from Basic Principle of Signal Display topic in portion Oscilloscopes of Electrical Measurements

Answer»

Right CHOICE is (d) voltage is synchronised

Explanation: The trace is made STATIONARY by SYNCHRONISING the sawtooth voltage with the MAGNITUDE of the signal that is applied to the vertical INPUT.

126.

Spot is displayed only when _______(a) frequencies are different(b) frequencies are zero(c) frequencies are same(d) voltage is highI have been asked this question in an online interview.My question is based upon Basic Principle of Signal Display topic in chapter Oscilloscopes of Electrical Measurements

Answer»

The correct ANSWER is (c) FREQUENCIES are same

For explanation: When the SWEEP frequency and the SIGNAL frequency are same or integral MULTIPLE of each other, visible spot is displayed on the screen of the cathode ray oscilloscope.

127.

Visible spot must be moved in _______(a) two directions(b) one direction(c) three directions(d) four directionsThe question was asked at a job interview.My doubt stems from Basic Principle of Signal Display topic in portion Oscilloscopes of Electrical Measurements

Answer»

Right choice is (b) one DIRECTION

The BEST I can explain: Sweep voltage must be brought to zero once it reaches its maximum value. The visible spot must be moved in a single direction only. RETURN sweep will trace BACK the signal in a REVERSE direction.

128.

Vertical deflection is given by ________(a) y = Ky Vy(b) y = Ky(c) x = 1(d) y = VyThe question was posed to me in my homework.This intriguing question comes from Cathode Ray Tube topic in portion Oscilloscopes of Electrical Measurements

Answer»

The correct CHOICE is (a) y = Ky Vy

The explanation: In a cathode ray TUBE the vertical DEFLECTION is given by,

y = Ky Vy

where, Ky is the CONSTANT of proportionality

y is the vertical deflection

Vy is the vertical deflecting voltage.

129.

What provides a periodic voltage waveform?(a) sweep generator(b) voltmeter(c) oscillator(d) amplifierThe question was posed to me by my school teacher while I was bunking the class.Question is from Basic Principle of Signal Display topic in division Oscilloscopes of Electrical Measurements

Answer»

The correct option is (a) sweep generator

The best I can explain: Sweep generator provides a periodic voltage WAVEFORM in an OSCILLOSCOPE. As the waveform resembles the TEETH of a HACKSAW it is known as a sawtooth waveform.

130.

Horizontal deflection is given by ________(a) x = Kx(b) x = Vx(c) x = 1(d) x = Kx VxThe question was asked during an online interview.My question is taken from Cathode Ray Tube in division Oscilloscopes of Electrical Measurements

Answer»

Correct option is (d) x = KX Vx

Explanation: In a cathode ray TUBE the horizontal deflection is given by,

x = Kx Vx

where, Kx is the CONSTANT of proportionality

x is the horizontal deflection

Vx is the horizontal deflecting VOLTAGE.

131.

Deflection system of a CRT consists of ________(a) 4 plates(b) 6 plates(c) 2 plates(d) 8 platesI have been asked this question in a national level competition.This key question is from Cathode Ray Tube topic in portion Oscilloscopes of Electrical Measurements

Answer»

Correct choice is (c) 2 plates

The best I can explain: Cathode ray tube consists of two sets of plates that are parallel in nature. They are REFERRED to as horizontal and vertical DEFLECTION plates. One of the plates is set to GROUND potential.

132.

Focusing and accelerating anodes are ________(a) rectangular(b) cylindrical(c) spherical(d) squareThis question was posed to me in an interview.Query is from Cathode Ray Tube in section Oscilloscopes of Electrical Measurements

Answer»

The correct CHOICE is (B) cylindrical

Easiest explanation: Focussing and accelerating anodes in a cathode ray tube are essentially cylindrical in nature. Each electrode has a SMALL opening at the centre with a co-axial TUBULAR axis.

133.

Electron beam diverges.(a) True(b) FalseThis question was addressed to me during an interview for a job.Question is from Cathode Ray Tube topic in portion Oscilloscopes of Electrical Measurements

Answer»

Correct choice is (a) True

Best explanation: Similar CHARGES on electrons lead to a repulsion. As a result the ELECTRON beam diverges as it CONTAINS MANY electrons. ELECTROSTATIC force is applied between the focussing anodes in order to compensate the repulsive force.

134.

Effect of negative voltage to the grid is ________(a) no force(b) a gravitational force(c) an attractive force(d) a repulsive forceThis question was addressed to me in an interview for internship.The query is from Cathode Ray Tube topic in section Oscilloscopes of Electrical Measurements

Answer»

The correct choice is (d) a repulsive FORCE

For explanation: SINCE the electron is negatively CHARGED, application of a negative VOLTAGE to the control grid PRODUCES a repulsive force.

135.

What determines light intensity in a CRT?(a) voltage(b) current(c) momentum of electrons(d) fluorescent screenThis question was posed to me in an interview.My query is from Cathode Ray Tube topic in division Oscilloscopes of Electrical Measurements

Answer» CORRECT answer is (c) momentum of electrons

The EXPLANATION is: Momentum of the electrons GIVES the INTENSITY or brightness of the light emitted from the fluorescent screen due to electron bombardment. It is given as the product of the no of electrons and their speed.
136.

Control grid is given ________(a) positive voltage(b) negative voltage(c) neutral voltage(d) zero voltageThis question was addressed to me in an online interview.Query is from Cathode Ray Tube topic in division Oscilloscopes of Electrical Measurements

Answer»

Right answer is (b) NEGATIVE voltage

For explanation I would say: Grid controls the amount of electrons falling on the FLUORESCENT SCREEN of a CATHODE ray tube. Cathode ray tube is provided with a negative voltage with respect to the cathode as a reference.

137.

Electron gun section ________(a) provides sharp beam(b) provides poorly focussed beam(c) doesn’t provide any beam(d) provides electrons onlyThis question was addressed to me by my school teacher while I was bunking the class.Query is from Cathode Ray Tube topic in section Oscilloscopes of Electrical Measurements

Answer»

The correct choice is (a) provides sharp beam

The EXPLANATION is: In a cathode RAY TUBE, the electron gun section GIVES a sharply focussed beam of electrons. They are focussed on the fluorescent coated screen.

138.

Typically oscilloscope represents __________(a) current and time(b) resistance and time(c) voltage and time(d) power and timeThe question was asked at a job interview.This is a very interesting question from Oscilloscope topic in section Oscilloscopes of Electrical Measurements

Answer»

The correct choice is (c) voltage and TIME

The best I can explain: In an oscilloscope TYPICALLY the HORIZONTAL or x-axis represents the time while the vertical or y-axis represents the variation in the magnitude of the INPUT signal.

139.

CRT is the heart of CRO.(a) True(b) FalseI got this question in unit test.This intriguing question originated from Oscilloscope in division Oscilloscopes of Electrical Measurements

Answer»

The correct choice is (a) True

Explanation: CRT stands for Cathode Ray Tube. It GENERATES electron beam, accelerates and DEFLECTS the beam. It THUS forms the HEART of the CRO.

140.

Electron beam is deflected in __________(a) 1 direction(b) 4 directions(c) 3 directions(d) 2 directionsThe question was posed to me during an internship interview.I want to ask this question from Oscilloscope in division Oscilloscopes of Electrical Measurements

Answer»

Right OPTION is (d) 2 directions

The BEST explanation: The ELECTRON beam in an oscilloscope can be deflected in two directions, NAMELY the horizontal (x-direction) and the vertical (y-direction). Two dimensional displays are PRODUCED as a result.

141.

CRO can’t display microseconds time.(a) True(b) FalseThe question was asked in an interview for job.Query is from Oscilloscope in division Oscilloscopes of Electrical Measurements

Answer»

The CORRECT answer is (B) False

The best I can explain: CRO is a fast x-y plotter and displays PERIODIC signals with time periods of the order of a few MICROSECONDS and even nanoseconds.

142.

CRO is a __________(a) fast x-y plotter(b) slow x-y plotter(c) medium x-y plotter(d) not a plotterI have been asked this question during an interview for a job.The question is from Oscilloscope in chapter Oscilloscopes of Electrical Measurements

Answer»

The correct ANSWER is (a) fast x-y PLOTTER

To ELABORATE: CRO is basically a fast x-y plotter. The x and y axes can be used to understand the variation in the MAGNITUDE of one voltage with respect to another voltage signal.

143.

Oscilloscope is __________(a) a ohmmeter(b) an ammeter(c) a voltmeter(d) a multimeterThe question was asked in an internship interview.My question comes from Oscilloscope in portion Oscilloscopes of Electrical Measurements

Answer»

Correct ANSWER is (C) a voltmeter

Best EXPLANATION: Oscilloscope is basically a voltmeter. It employs the MOVEMENT of an electronic gun assembly with respect to a fluorescent screen. The screen produces the movement of the visible SPOT.

144.

C.R.O gives __________(a) actual representation(b) visual representation(c) approximate representation(d) incorrect representationI got this question during an interview for a job.Asked question is from Oscilloscope in section Oscilloscopes of Electrical Measurements

Answer»

Right option is (b) VISUAL representation

Explanation: Cathode RAY OSCILLOSCOPE is used as universal LABORATORY equipment.It provides a visual representation of time varying signals. It is an important equipment in the development of electronic circuits.

145.

CRO stands for __________(a) Cathode Ray Oscilloscope(b) Current Resistance Oscillator(c) Central Resistance Oscillator(d) Capacitance Resistance OscilloscopeThis question was addressed to me by my college professor while I was bunking the class.This question is from Oscilloscope topic in chapter Oscilloscopes of Electrical Measurements

Answer»

The correct answer is (a) Cathode Ray Oscilloscope

The best EXPLANATION: Cathode Ray Oscilloscope (C.R.O) is basically USED for the MEASUREMENT of the amplitude of periodic and non periodic signals as a FUNCTION of TIME.