Working of CRO

Q. Trigger pulses in the CRO are used

1. to generate high voltage required for the CRT
2. to synchronize the input and the vertical amplifier.
3. to synchronize the input with the time base generator
4. to generate low voltage required for the CRT

Q. A CRT has an anode voltage of 1500 V and parallel plates are 1.5 cm long and 5 mm apart. The screen is 50 cm away from centre of the plates. The input voltage is applied to the deflecting plates through amplifier. The input voltage required for a deflection of 4 cm is 2 V (through amplifier). Which of the following are correct?

1. Gain of amplifier is 60
2. Gain of amplifier is 40
3. Voltage applied to deflecting plates is 80 V.
4. Voltage applied to deflecting plates is 120 V.

Q. The horizontal deflection plates in a cathode ray tube are 30 mm long and 5 mm apart. The centre of these plates is 60 cm from the screen, accelerating plate voltage is 3000 V. The deflection sensitivity is _______ mm/V.

1. 0.6

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

1. both x and y plate
2. y plate
3. Neither x nor y plates
4. x plate

Q. Regarding mode of operation of CRO which of following statement is not correct.

1. Single beam CRO can show alternate and chop mode of operation both.
2. For multiple input CRO attenuators and preamplifiers are provided separately.
3. The display signal is blanked during flyback period, but not in hold off period, in CRO operation.
4. Dual trace CRO is not better option when we are comparing two fast changing transients.