Cathode Ray Oscilloscope CRO MCQ

Cathode Ray Oscilloscope CRO MCQ. These 100 Multiple Choice Questions on Cathode Ray Oscilloscope will help you score full marks in your exam.

I. Introduction to CROs: Cathode Ray Oscilloscope CRO MCQ

Basic Principles

Question 1: What is the primary purpose of a Cathode Ray Oscilloscope (CRO)?

A. To generate electrical signals

B. To measure and display electrical waveforms

C. To amplify electronic sounds

D. To store digital data

Question 2: Which of the following is NOT a core component of a CRO?

A. Cathode Ray Tube (CRT)

B.  Hard Drive

C.  Vertical Amplifier

D. Timebase Generator

Question 3:  What does CRO stand for in the context of electronics?

A.  Centralized Reporting Office

B.  Cathode Ray Oscilloscope

C.  Critical Research Operation

D.  Capacitor-Resistor Oscillator

Historical Development and Evolution of CROs

Question 4: Early CROs primarily used what type of technology for their display?

A.  Liquid Crystal Displays (LCDs)

B.  Light Emitting Diodes (LEDs)

C.  Cathode Ray Tubes (CRTs)

D.  Plasma Displays

Question 5: How have modern CROs evolved compared to their earlier counterparts?

A.  They are exclusively analog

B.  They are larger and less portable

C.  They have limited functionality

D.  They often incorporate digital technology and advanced features

Types of CROs

Question 6: Which type of CRO offers the capability to store and analyze waveforms?

A.  Analog CRO

B.  Digital Storage Oscilloscope (DSO)

C.  Mechanical Oscilloscope

D.  Optical Oscilloscope

Question 7: What is a key advantage of a digital CRO over an analog CRO?

A.  Limited display capabilities

B.  Inability to store waveforms

C.  Increased portability and ruggedness

D.  Lower bandwidth

Applications of CROs

Question 8:  In which field are CROs NOT commonly used?

A.  Electronics

B.  Medicine

C.  Culinary Arts

D.  Engineering

Question 9: How are CROs utilized in the medical field?

A.  To monitor patient’s vital signs like heart rate

B.  To perform complex surgical procedures

C.  To dispense medication

D.  To conduct psychological evaluations

Question 10:  What type of signal can a CRO visualize and measure?

A.  Only audio signals

B.  Only radio waves

C.  A wide range of electrical signals (voltage, current, etc.)

D.  Exclusively digital signals

Cathode Ray Tube (CRT)

Question 11: Which component of a CRT is responsible for emitting electrons?

A. Deflection plates

B. Electron gun

C. Fluorescent screen

D. Anode

Question 12: What is the function of the deflection plates in a CRT?

A. To emit electrons

B. To accelerate electrons

C. To focus electrons

D. To steer the electron beam

Question 13: What material is the fluorescent screen in a CRT typically coated with?

A.  Aluminum

B.  Phosphor

C.  Silver

D.  Gold

Question 14: How is the electron beam generated in a CRT?

A. By heating a cathode

B. By applying a magnetic field

C. By using a laser

D. By chemical reaction

Question 15: What is the role of the control grid in an electron gun?

A. To deflect the electron beam

B. To accelerate the electron beam

C. To focus the electron beam

D. To regulate the intensity of the electron beam

Question 16: How is the electron beam focused in a CRT?

A. Using magnetic fields

B. Using electrostatic fields

C. Using both magnetic and electrostatic fields

D. Using a lens

Question 17: What causes the electron beam to accelerate towards the screen in a CRT?

A. A high positive voltage applied to the anode

B. A high negative voltage applied to the cathode

C. A magnetic field

D.  Gravity

Question 18: What are the two main methods for deflecting the electron beam in a CRT?

A.  Electrostatic and electromagnetic

B.  Gravitational and inertial

C.  Thermal and optical

D.  Chemical and nuclear

Question 19: What is the phenomenon called when the phosphor screen emits light after being struck by the electron beam?

A.  Reflection

B.  Refraction

C.  Fluorescence

D.  Diffraction

Question 20: What is the difference between fluorescence and phosphorescence?

A.  Fluorescence is the emission of light only in the visible spectrum, while phosphorescence includes UV and infrared.

B.  Fluorescence is the immediate emission of light, while phosphorescence persists after the excitation source is removed.

C.  There is no difference; they are the same phenomenon.

D.  Fluorescence refers to red light emission, and phosphorescence refers to blue light emission.

II. CRO Operation and Controls: Cathode Ray Oscilloscope CRO MCQ

Front Panel Controls

Question 21: Which control adjusts the brightness of the displayed waveform on a CRO?

A. Focus

B. Intensity

C.  Time/div

D. Trigger

Question 22: What is the purpose of the focus control on a CRO?

A. To adjust the brightness of the trace

B. To sharpen the waveform display

C. To change the horizontal position of the trace

D. To control the vertical sensitivity

Question 23: What does the “Volts/div” control on a CRO determine?

A. The timebase setting

B. The vertical sensitivity of the display

C. The trigger level

D. The input impedance

Question 24:  What is the function of the “Time/div” control on a CRO?

A.  To adjust the horizontal scale of the display

B.  To control the vertical sensitivity

C.  To change the trigger mode

D.  To set the input impedance

Question 25: What is the purpose of the trigger control on a CRO?

A. To adjust the brightness of the trace

B. To stabilize the waveform display

C. To change the vertical position of the trace

D. To control the input impedance

Question 26: What is the primary function of the vertical amplifier in a CRO?

A. To generate the timebase signal

B. To amplify or attenuate the input signal

C. To deflect the electron beam horizontally

D. To focus the electron beam

Question 27: What does AC/DC coupling in a CRO’s vertical amplifier refer to?

A. The type of power supply used by the CRO

B. The ability to display both AC and DC components of a signal

C. The type of probe used with the CRO

D. The internal resistance of the CRO

Question 28: What is the input impedance of a CRO?

A. The resistance of the vertical amplifier input

B. The capacitance of the vertical amplifier input

C. The inductance of the vertical amplifier input

D. The combination of resistance and capacitance at the input

Question 29: What is the effect of limited bandwidth in a CRO’s vertical amplifier?

A. Increased display brightness

B. Distortion of high-frequency signals

C. Improved trigger stability

D. Enhanced vertical sensitivity

Question 30: What is the purpose of the timebase generator in a CRO?

A. To amplify the input signal

B. To generate the horizontal sweep signal

C. To trigger the vertical amplifier

D. To focus the electron beam

Horizontal Sweep

Question 31: Which triggering mode on a CRO is best for capturing single events?

A. Auto

B. Normal

C. Single

D. Free-run

Question 32:  What is the purpose of the trigger source selection on a CRO?

A. To choose the signal that initiates the horizontal sweep

B. To adjust the brightness of the trace

C. To select the type of probe

D. To change the vertical sensitivity

Question 33: What does adjusting the trigger level control on a CRO do?

A. Changes the focus of the waveform

B. Sets the voltage level that triggers the horizontal sweep

C. Alters the timebase setting

D. Modifies the input impedance

Display System

Question 34: What is the grid on the CRO screen called?

A.  Reticle

B.  Graticule

C.  Matrix

D.  Mesh

III. CRO Measurements and Applications: Cathode Ray Oscilloscope CRO MCQ

Voltage Measurement

Question 35: What is peak-to-peak voltage?

A. The average voltage of a signal

B. The difference between the maximum and minimum voltage levels of a signal

C. The RMS voltage of a signal

D. The DC offset of a signal

Question 36: How is the amplitude of a signal measured on a CRO?

A. By measuring the time period of the signal

B. By measuring the peak-to-peak voltage and dividing by two

C. By measuring the DC offset of the signal

D. By counting the number of cycles displayed

Question 37: What is DC offset in a signal?

A. The average voltage of the AC component of a signal

B. The difference between the maximum and minimum voltage levels of a signal

C. The DC component of a signal that shifts the waveform up or down

D. The frequency of the signal

Question 38: How does vertical sensitivity affect voltage measurements on a CRO?

A. It determines the timebase setting

B. It changes the scale of the voltage measurement on the vertical axis

C. It affects the trigger level

D. It modifies the input impedance

Question 39: What is probe attenuation?

A. The amplification of the signal by the probe

B. The reduction of the signal amplitude by the probe

C. The distortion of the signal by the probe

D. The change in the signal frequency by the probe

Time and Frequency Measurement

Question 40: How is the time period of a periodic signal measured on a CRO?

A. By measuring the distance between two consecutive peaks on the horizontal axis and multiplying by the time/div setting

B. By measuring the peak-to-peak voltage of the signal

C. By measuring the DC offset of the signal

D. By measuring the amplitude of the signal

Question 41: How is the frequency of a periodic signal calculated from its time period?

A. Frequency = Time period

B. Frequency = 1 / Time period

C. Frequency = Time period² 

D. Frequency = √Time period

Question 42: What is pulse width?

A. The time period of a pulse signal

B. The amplitude of a pulse signal

C. The duration of the “on” state of a pulse signal

D. The frequency of a pulse signal

Question 43: How can the timebase and trigger controls be used for accurate time measurements?

A. By adjusting the intensity of the trace

B. By stabilizing the waveform display and selecting an appropriate time/div setting

C. By changing the vertical position of the trace

D. By controlling the input impedance

Phase Measurement

Question 44: What are Lissajous figures used for in CRO measurements?

A. Measuring voltage

B. Measuring frequency

C. Determining phase difference between two signals

D. Analyzing waveform distortion

Question 45: What is phase shift?

A. The difference in amplitude between two signals

B. The difference in frequency between two signals

C. The time delay between two signals with the same frequency

D. The distortion of a signal

Waveform Analysis

Question 46: Which of the following is NOT a common waveform shape displayed on a CRO?

A. Sine wave

B. Square wave

C.  Parabolic wave

D. Triangle wave

Question 47: What does waveform distortion refer to?

A.  A perfect sine wave

B.  Any deviation from the ideal shape of a waveform

C.  A stable waveform display

D.  A change in the frequency of a signal

Question 48: What can cause waveform anomalies on a CRO display?

A.  Proper probe compensation

B.  Accurate trigger settings

C.  Faulty equipment or interference

D.  A clean and stable input signal

Applications 

Question 49: How can a CRO be used for troubleshooting electronic circuits?

A. By measuring temperature

B. By identifying faulty components or signal abnormalities

C. By generating audio signals

D. By storing digital data

Question 50: What role do CROs play in communication systems?

A. They amplify audio signals

B. They analyze signal characteristics like modulation and distortion

C. They transmit radio waves

D. They store digital data

Question 51: How can CROs be used to observe physical phenomena?

A. By directly measuring temperature

B. By converting physical phenomena into electrical signals that can be displayed

C. By generating X-rays

D. By performing chemical analysis

IV. Probes and Accessories: Cathode Ray Oscilloscope CRO MCQ

Types of Probes

Question 52: What is the main difference between passive and active probes?

A.  Passive probes require an external power source, while active probes do not.

B.  Active probes have built-in amplifiers, while passive probes do not.

C.  Passive probes are used for high-frequency measurements, while active probes are used for low-frequency measurements.

D.  There is no difference; they are functionally the same.

Question 53: What are high-voltage probes used for?

A. Measuring signals in low-voltage circuits

B. Measuring signals in high-voltage circuits without damaging the CRO

C. Measuring current

D. Measuring temperature

Question 54: Why are specialized probes needed for certain CRO applications?

A.  All probes are the same; specialized probes are not necessary.

B.  To adapt to specific measurement requirements, such as current measurement or high-frequency signals.

C.  To change the color of the waveform display.

D.  To adjust the intensity of the electron beam.

Probe Compensation

Question 55: What is the purpose of probe compensation?

A. To increase the signal amplitude

B. To adjust the probe’s capacitance to ensure accurate measurements

C. To change the probe’s input impedance

D. To reduce noise

Question 56: Why is probe compensation important?

A. It is not important; probes are always accurate.

B. It prevents damage to the CRO.

C. It ensures that the probe does not load the circuit under test and maintains signal fidelity.

D. It increases the brightness of the display.

Other Accessories

Question 57: What is the function of a signal generator in conjunction with a CRO?

A. To display waveforms

B. To provide a known signal source for testing circuits

C. To measure voltage

D. To measure current

V. Advanced CRO Features and Techniques: Cathode Ray Oscilloscope CRO MCQ

Digital Storage Oscilloscopes (DSOs)

Question 58: What is a key advantage of a Digital Storage Oscilloscope (DSO) over an analog CRO?

A.  DSOs can only display simple waveforms.

B.  DSOs cannot capture transient events.

C.  DSOs have limited memory for storing waveforms.

D.  DSOs can store waveforms for later analysis and comparison.

Question 59: What does the sampling rate of a DSO determine?

A. The brightness of the display

B. The number of waveform samples captured per second

C. The input impedance of the oscilloscope

D. The accuracy of the trigger

Question 60: What is the resolution of a DSO?

A. The number of vertical divisions on the screen

B. The number of horizontal divisions on the screen

C. The number of bits used to represent each waveform sample

D. The maximum frequency that can be displayed

Advanced Triggering

Question 61: What is pulse width triggering?

A. Triggering on a pulse with a specific duration

B. Triggering on the rising or falling edge of a signal

C. Triggering on a video signal

D. Triggering on a pattern of logic levels

Question 62: What is edge triggering?

A. Triggering on a pulse with a specific duration

B. Triggering on the rising or falling edge of a signal

C. Triggering on a video signal

D. Triggering on a pattern of logic levels

Question 63: What is the purpose of pattern triggering?

A. To trigger on a single pulse

B. To trigger on a specific sequence of logic levels

C. To trigger on a video signal

D. To trigger on a specific frequency

Math Functions

Question 64: What kind of mathematical operations can be performed on waveforms using a DSO with math functions?

A. Only addition

B. Only subtraction

C. Addition, subtraction, multiplication, and other operations

D. No mathematical operations can be performed

Question 65: How can math functions be used for signal analysis and comparison?

A. To change the color of the waveform display

B. To adjust the intensity of the electron beam

C. To perform calculations on waveforms, such as adding or subtracting signals

D. To generate audio signals

Spectrum Analysis

Question 66: What is FFT (Fast Fourier Transform) used for in CROs?

A. To measure voltage

B. To measure time period

C. To analyze the frequency content of a signal

D. To display Lissajous figures

VI. Safety Precautions: Cathode Ray Oscilloscope CRO MCQ

Electrical Safety

Question 67: What is the most important safety precaution when working with CROs and high voltages?

A. Wearing safety glasses

B. Avoiding contact with any live circuits or connections

C. Using a high-voltage probe

D. Turning off the CRO before making any connections

Question 68: Why is proper grounding important when using a CRO?

A. To increase the brightness of the display

B. To prevent electric shock and ensure accurate measurements

C. To protect the CRO from damage

D. To reduce noise

CRT Safety

Question 69: Why should CRTs be handled with care?

A. To prevent implosion and potential exposure to harmful materials

B. Because they are very expensive

C. Because they are sensitive to light

D. Because they can easily overheat

Question 70: How should CRTs be disposed of?

A. They can be thrown in the regular trash.

B. They should be recycled according to local regulations for electronic waste.

C. They can be burned.

D. They can be buried in the ground.

Question 71:  Which of the following is NOT a potential hazard associated with CRTs?

A.  Implosion

B.  Electric shock

C.  X-ray exposure

D.  Excessive heat generation

Question 72:  What is the primary reason for concern about X-ray exposure from CRTs?

A.  CRTs emit high levels of X-rays that can cause immediate harm.

B.  Long-term exposure to even low levels of X-rays can have health consequences.

C.  X-rays from CRTs can interfere with other electronic devices.

D.  X-rays from CRTs can cause the screen to lose its brightness.

Question 73:  Why is it important to avoid touching the back of a CRT, especially when it is operating?

A.  The back of the CRT can get very hot.

B.  The back of the CRT can contain high voltages that pose a risk of electric shock.

C.  Touching the back of the CRT can distort the display.

D.  Touching the back of the CRT can damage the internal components.

Question 74: What should you do if you notice any cracks or damage to a CRT?

A. Continue to use it cautiously.

B. Attempt to repair it yourself.

C.  Dispose of it immediately and handle it with extra care to prevent further damage.

D.  Ignore the damage and continue using it as normal.

Question 75: Which of the following is a safe practice when working with a CRO?

A.  Leaving the CRO powered on when not in use.

B.  Disconnecting the probe ground before turning off the CRO.

C.  Using only one hand when making adjustments to the CRO settings.

D.  Ensuring the CRO is properly grounded.

Question 76: Why is it important to disconnect the CRO from the power source before replacing any components?

A. To prevent electric shock.

B. To avoid damaging the new component.

C. To prevent data loss.

D. To ensure the new component is compatible.

Question 77: What type of safety glasses should be worn when working with CRTs?

A.  Sunglasses

B.  Reading glasses

C.  Safety glasses with impact and shatter resistance

D.  Any type of glasses will provide sufficient protection

Question 78: What is the purpose of a high-voltage probe?

A.  To increase the voltage of the signal being measured.

B.  To allow safe measurement of high voltages.

C.  To measure current.

D.  To measure resistance.

Question 79: What should you do if you accidentally come into contact with a live circuit while using a CRO?

A.  Quickly pull your hand away.

B.  Turn off the power source immediately.

C.  Do nothing and wait for the shock to pass.

D.  Try to ground yourself.

Question 80: Where should CROs be stored when not in use?

A.  In a damp environment.

B.  In direct sunlight.

C.  In a clean, dry environment away from excessive heat or moisture.

D.  It doesn’t matter where they are stored.

Question 81:  What should you do before cleaning the screen of a CRO?

A.  Use a damp cloth to wipe the screen.

B.  Spray cleaning solution directly onto the screen.

C.  Disconnect the CRO from the power source.

D.  Wear gloves to prevent electric shock.

Question 82: Why is it important to use a properly rated fuse in a CRO?

A. To prevent damage to the CRO in case of a power surge or fault.

B. To increase the brightness of the display.

C. To improve the accuracy of measurements.

D. To reduce noise.

Question 83: What is the purpose of an isolation transformer when using a CRO?

A. To amplify the signal being measured.

B. To provide electrical isolation between the CRO and the circuit under test.

C. To convert AC voltage to DC voltage.

D. To measure current.

Question 84:  Which of the following is a good practice for cable management when using a CRO?

A.  Leaving cables tangled and disorganized.

B.  Securing cables to prevent tripping hazards and accidental disconnections.

C.  Running cables across walkways.

D.  Using damaged or frayed cables.

Question 85: Why is it important to follow the manufacturer’s instructions when using a CRO?

A.  To ensure optimal performance and safety.

B.  The manufacturer’s instructions are not important.

C.  To avoid voiding the warranty.

D.  To impress your colleagues.

Question 86: What should you do if you are unsure about a safety procedure when working with a CRO?

A.  Proceed with caution and hope for the best.

B.  Ask a colleague for advice.

C.  Consult the user manual or seek guidance from a qualified instructor or technician.

D.  Experiment until you figure it out.

Question 87:  Why is it important to keep the CRO’s ventilation openings clear?

A.  To prevent the CRO from overheating.

B.  To improve the accuracy of measurements.

C.  To reduce noise.

D.  To enhance the display’s brightness.

Question 88: What is the purpose of a circuit breaker in a CRO?

A.  To protect the CRO from damage due to excessive current.

B.  To adjust the brightness of the display.

C.  To improve the accuracy of measurements.

D.  To reduce noise.

Question 89: What should you do if you spill liquid on a CRO?

A.  Wipe it up immediately with a damp cloth.

B.  Disconnect the CRO from the power source and allow it to dry completely before using it again.

C.  Continue using the CRO as normal.

D.  Blow dry the liquid.

Question 90:  Why is it important to have the CRO calibrated regularly?

A.  To ensure accurate measurements.

B.  To prevent the CRO from overheating.

C.  To reduce noise.

D.  To enhance the display’s brightness.

Question 91: What is the best way to learn how to use a CRO safely and effectively?

A.  Trial and error.

B.  Watching online videos.

C.  Reading the user manual and seeking guidance from qualified instructors.

D.  Asking a friend.

Question 92: Why is it important to be aware of the potential hazards when working with a CRO?

A.  To avoid accidents and ensure personal safety.

B.  To impress your colleagues.

C.  To avoid damaging the CRO.

D.  To get a higher grade in your electronics class.

Question 93: What is the first thing you should do if you suspect a malfunction with your CRO?

A.  Attempt to repair it yourself.

B.  Continue using it cautiously.

C.  Disconnect it from the power source and consult the user manual or seek assistance from a qualified technician.

D.  Ignore the malfunction and hope it goes away.

Question 94:  Why is it important to avoid using excessive force when connecting probes or cables to a CRO?

A.  To prevent damage to the connectors.

B.  To improve the accuracy of measurements.

C.  To reduce noise.

D.  To enhance the display’s brightness.

Question 95: What is the purpose of a safety interlock on a CRO?

A.  To prevent access to high voltages when the cover is removed.

B.  To adjust the brightness of the display.

C.  To improve the accuracy of measurements.

D.  To reduce noise.

Question 96:  When should you replace the batteries in a portable CRO?

A.  Only when they are completely dead.

B.  When the low battery indicator appears or as recommended by the manufacturer.

C.  Every six months.

D.  Never, as portable CROs do not use batteries.

Question 97:  Why is it important to avoid using a CRO in an environment with strong magnetic fields?

A.  Strong magnetic fields can interfere with the CRO’s operation and affect measurements.

B.  Strong magnetic fields can damage the CRO.

C.  Strong magnetic fields can cause electric shock.

D.  Strong magnetic fields can cause the display to become distorted.

Question 98: What is the purpose of a protective cover for a CRO?

A.  To keep the CRO clean and prevent dust buildup.

B.  To improve the accuracy of measurements.

C.  To reduce noise.

D.  To enhance the display’s brightness.

Question 99:  What should you do before transporting a CRO?

A.  Leave it powered on.

B.  Disconnect all probes and cables and pack it securely in its carrying case.

C.  Place it in a plastic bag.

D.  Carry it by the screen.

Question 100: Why is it important to consult the user manual before operating a CRO for the first time?

A.  To familiarize yourself with the specific features and safety precautions for that model.

B.  User manuals are not important.

C.  To avoid voiding the warranty.

D.  To impress your colleagues.

Most Asked Questions on Cathode Ray Oscilloscope

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