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

Answer
Answer. b

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

Answer
Answer. b

3. A CRO can be used to measure

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

Answer
Answer. d

4. Cathode Of CRO is coated with

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

Answer
Answer. c

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

Answer
Answer. b

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

Answer
Answer. d

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

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

Answer
Answer. a

8. Horizontal deflection plates of CRO are placed generally

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

Answer
Answer. 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

Answer
Answer. c

10. A CRO cannot be used for direct measurement of

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

Answer
Answer. d

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

Answer
Answer. b

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

Answer
Answer. b

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

Answer
Answer. a

14. A CRO can display  ____

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

Answer
Answer. d

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

Answer
Answer. a

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

Answer
Answer. a

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

Answer
Answer. d

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

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

Answer
Answer. a

19. The input impedance of CRO is about

  1. 10 Ω
  2. 100 Ω
  3. 1 MΩ

Answer
Answer. d

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

 

Answer
Answer. d