# Cathode Ray Oscilloscope (CRO) MCQ Posted by

## Cathode Ray Oscilloscope (CRO) MCQ

Cathode Ray Oscilloscope (CRO) MCQ, Multiple choice question on Cathode Ray Oscilloscope (CRO), GATE Questions on Cathode Ray Oscilloscope (CRO), Objective questions with answer on Cathode Ray Oscilloscope (CRO), Engineering MCQ

### Multiple Choice Questions

Q.1. In a CRT the focusing anode is located

• Between pre-accelerating and accelerating anodes
• After pre-accelerating anode
• None of the above

Answer: Between pre-accelerating and accelerating anodes

Q.2. The source of emission of electrons in a CRT is

• PN function diode
• A barium and strontium oxide coated cathode
• Accelerating anodes
• Post-accelerating anodes

Answer: A barium and strontium oxide coated cathode

Q.3. Post acceleration is needed in a CRO if the frequency of the signal is:

• Less than 1 MHz
• More than 1 MHz
• More than 10 MHz
• More than 10 Hz

Q.4. The deflection of an electron beam on a CRT screen is 10 mm, Suppose the pre-accelerating anode voltage is halved and the potential between deflecting plates is doubled, the deflection of the electron beam will be:

• 80 mm
• 40 mm
• 20 mm
• 10 mm

Q.5. If the distance of screen from a CRT to centre of deflection plates is 15 cm. The length of deflection plates is 2 cm, the distance between plates is 1 cm and the accelerating voltages is 500 V, the deflection sensitivity is:

• 33.2 V/cm
• 0.03 cm/V
• 66.4 V/cm
• 0.015 cm/V

Q.6. The horizontal amplifier should be designed for

• High frequency signals with a fast rise time
• High amplitude signals with a slow rise time
• High amplitude signals with a fast rise time
• Low amplitude signals with a fast rise time

Answer: High amplitude signals with a slow rise time

Q.7. P1 phosphor material is used for display in CRTs for:

• Photographic applications
• General purpose applications
• Television applications
• All of the above

Q.8. An aquadag is used in a CRO to collect:

• Primary electrons
• Secondary emission electrons
• Both primary and secondary emission electrons
• None of the above

Q.9. A thin aluminum film is usually deposited on the non viewing side of the phosphor because,

• Its acts as a heatsink and prevents phosphor burn
• The lighter scatter from the phosphor is reduced
• It does not allow the screen to be negatively charged
• All of the above

Q.10. During the retrace time, the electrons forming the horizontal beam.

• Move from left to right on the screen
• Move from right to the left on the screen
• Move from bottom to top of screen
• Move from top to bottom of screen

Answer: Move from right to the left on the screen

Q.11. A vertical amplifier for a CRO can be designed for:

• Only a high gain
• A constant gain times bandwidth product
• All of the above

Answer: A constant gain times bandwidth product

Q.12. In an oscilloscope, when the unknown signal applied to the vertical plates is being synchronized with the sweep signal applied to horizontal plates, the pattern seen on the CRO screen moves towards the right. It means that,

• The frequency of the signal is lower than of the sweep signal
• The frequency of the signal greater than of the sweep signal
• The frequency of the signal is equal to the frequency of sweep signal
• None of the above

Answer:  The frequency of the signal is lower than of the sweep signal

Q.13. The sine wave output of a function generator is fed to both the horizontal (X) and vertical (Y) inputs of a CRO. What will be the pattern on the cathode ray screen?

• Circle
• An ellipse
• A straight line with 45° slope
• Sinusoidal

Answer: A straight line with 45° slope

Q.14. Which one of the following is the correct statement? Active probe used in a CRO,

• Is bulk then passive ones
• Cannot measure small signals
• Cannot couple high frequency signals
• Can attenuate more

Answer: Cannot couple high frequency signals

Q.15. A circle is found on the screen of a CRO when 2 time varying signals of same frequency and same magnitude are applied to X and Y plates of the CRO. What is the relative phase difference?

• 90°
• 180°
• 45°

Q.16. A compensated probe of a CRO contains which of the following ?

• An amplifier
• R-O network
• Only resistive network
• Only capacitive network

Q.17. A 1000 Hz sinusoidal voltage is connected to both X and Y inputs of a CRO. Which of the following waveforms is seen on CRO?

• Sine Wave
• Circle
• Ellipse
• Straight Line

Q.18. While measuring the phase difference between the signals V1(t) = 10 sin ωt and V2(t) = 10 sin (ωt + q), the Lissajous pattern observed on CRO was a circle. The value of q is,

• 2 MHz
• 1 MHz
• 4 kHz
• 2 kHz

Q.19. The X and Y inputs to a CRO are respectively 10 cos (100t + θ) and 10 sin (ωt + q) the resulting Lissajous pattern is,

• A straight line inclined at an angle θ
• A horizontal line
• An ellipse with axis making an angle θ
• A circle