Cathode Ray Oscilloscope-CRO MCQ

1. The purpose of synchronizing control in CRO is to

1. focus the spot on the screen
2. lock the display of the signal
3. adjust the amplitude of display
4. control the intensity of spot

2. The rise time ‘t’ of a signal applied to CRO and bandwidth ‘B’ of the CRO are related as

1. t x B = 1
2. t x B = 0.35
3. t/B = 0.55
4. t/B = 0.32

3. A CRO can be used to measure

1. a.c. voltage
2. d.c. voltage
3. frequency
4. All of the above

4. Cathode Of CRO is coated with

1. Alkali material
2. thorium oxide
3. copper oxide
4. barium oxide

5. The technique of adding a precise amount of time between the trigger point and the beginning of the scope sweep in a CRO is known as

1. free running  sweep
2. delayed sweep
3. triggered sweep
4. non-sawtooth sweep

6. In a CRO, a sinusoidal waveform of a certain frequency is displayed. The value of the quantity that can be made out by observation is

1. RMS value of the sine wave
2. average value of the sine wave
3. form factor of the sine wave
4. peak-peak value of the sine wave

7. Lissajous pattern obtained on a CRO screen is a circle. frequency of two signals are

1. equal
2. unequal
3. zero
4. infinity

8. Horizontal deflection plates of CRO are placed generally

1. horizontal
2. vertical
3. diagonal
4. (a) or (b)

9. An oscilloscope is basically designed to convert

1. visual signals to electrical signals
2. sound signals to electrical signals
3. electrical signals to visual signals
4. sound signals to visual signals

10. A CRO cannot be used for direct measurement of

1. voltage
2. current
3. frequency
4. power

11. Which meter is suitable for the measurement of 10 mV at 50 MHz?

1. moving iron voltmeter
2. CRO
3. electrostatic voltmeter
4. VTVM

12. In a cathode ray tube, the focussing anode is located

1. after accelerating anode
2. between pre-accelerating and accelerating anodes
3. before pre-accelerating anode
4. just after electron-gun

13. A CRO indicates

1. peak to peak value of voltage
2. RMS value of voltage
3. average value of voltage
4. DC value of voltage

14. A CRO can display  ____

1. a.c. signal 
2. d.c. signal
3. time-invariant
4. both a.c. and d.c. signal

15. The input resistance of a cathode ray oscilloscope is of the order of ____

mega ohm

tens of ohm

kilo ohm

fraction of an ohm

16. The Y plates of a CRO are excited by a voltage 2 sin100t and the X plates are not connected. The display would be

1. a vertical line
2. a horizontal line
3. sine wave
4. a big dot

17. In a CRO which of the following is not a part of the electron gun

1. Cathode
2. grid
3. accelerating anode
4. X-Y plates

18. In a CRO, the sensitivity can be increased by ………….

1. decreasing the value of accelerating voltage E_a
2. increasing the value of accelerating voltage E_a
3. increasing the separation between the  deflecting plates
4. none of these

19. The input impedance of CRO is about

1. 0 
2. 10 Ω
3. 100 Ω
4. 1 MΩ

20. When measuring phase angle between two waves using a CRO, the time base generator is connected to

1. X plate
2. Y plate
3. both X and Y plates
4. neither X nor Y plates