24-09-2017, 11:22 AM
What is highest voltage that can be measured by c. R. O available in laboratory
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cro viva question and answers pdf
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What is highest voltage that can be measured by c. R. O available in laboratory
25-09-2017, 11:11 AM
Q1. What is a cathode ray oscilloscope (CRO)?
Ans: A CRO is an electronic device with a CRT as its main component and other associated circuits consisting of a power supply unit, a sawtooth wave generator, horizon and vertical amplifiers.
Q2. How is CRO superior to ordinary measuring instruments?
Ans: CRO is an electronic device that graphically displays the alternate quantities under examination. The CRO gives very accurate measurements and is free of errors introduced by moving parts. It is also of damping mechanisms and other parts containing inertia.
Q3. Why are vertical and horizontal plates provided in a CRO?
Ans: Horizontal and vertical plates are provided between the electron gun and the screen to deflect the beam according to the input signal.
Q4. Why is a trip circuit provided in a CRO?
Ans: In a CRO, a trigger circuit is provided to synchronize two types of deflections so that the horizontal deflection begins at the same point of the vertical input signal each time it is swept.
Q5. What are the essential components of a CRT?
Ans: The essential components of a CRT are electron guns, focusing and acceleration anodes, horizontal and vertical deflection plates, and evacuated glass casing with phosphorescent screen.
Q6. For what set of electron guns is provided in CRT?
Ans: The only function of an electron gun assembly in a CRO is to provide a narrow and focused electron beam with agility accelerates towards the phosphor screen.
Q7. Why is the grid in a CRO provided with a hole in it?
Ans: The hole in a grid of a CRO is provided to allow passage for the electrons through it and to concentrate the beam of electrons along the axis of the tube.
Q8. What is meant by the sensitivity of deviation of a CRO?
Ans: The deflection sensitivity of a CRO is defined as the vertical deflection of the beam on the screen per unit of deflection voltage.
Q9. What is meant by the deflection factor of a CRO?
Ans: The deflection factor of a CRO is the reciprocal of the deflection sensitivity.
Q10. What is the control of Astigmatism?
Ans: The astigmatism control is a setting that will provide a sharp focus across the screen.
Q11. What is the grid?
Ans: The grid is a scale on transparent material that fits the face of the CRT for the purpose of the measurement.
Q12. What is aquadag?
Ans: The coating of a conductive material, known as aquadag, is provided on the inner surface of the CRT to accelerate the electron beam after passing between the deflating plates and collecting electrons produced by the secondary emission when the electron beam strikes the screen.
Q13. What is meant by return time?
Ans: The delay time is the time required by the electron beam to return to its original position on a CRT screen after being shifted to the right by a sawtooth waveform.
Q14. What is Sweep Time?
Ans: The scanning time is the duration of time during which the beam is swept from left to right on the screen of a CRT by the linearly increasing sawtooth voltage.
Q15. What is a Lissajous pattern?
Ans: The Lissajous pattern is a pattern resulting from the application of periodic signals to the deflection plates of a CRO.
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