1. . The cathode of a C.R.O. is usually coated with
(A) Alkali metals
(B) Barium or strontium oxide
(C) Copper oxide
(D) Tungsten or thorium oxide
2. . The input impedance of C.R.O. is
(A) Zero
(B) Around 100 ohms
(C) Around 1000 ohms
(D) Around one mega-ohms
3. . A C.R.O. can be used to measure
(A) A.C. voltages only
(B) Any of the above
(C) Frequency
(D) D.C. voltages only
4. . A cathode ray oscilloscope consists of
(A) All of above
(B) The deflecting plates
(C) A fluorescent screen
(D) The electron gun
5. . In C.R.O, the grid is connected to the
(A) Negative potential
(B) Positive potential
(C) Alternating current (AC) source
(D) Direct current (DC) source
6. . An instrument which is used to display the magnitudes of changing electric currents or potentials is called
(A) Cathode-ray oscilloscope
(B) Gastro-scope
(C) Microscope
(D) Cystoscopy
7. . Who among the following developed the CRT (Cathode Ray Tube)?
(A) Charles Darwin
(B) Thomas Alva Edison
(C) Ferdinand Braun
(D) None of the above
8. . The inside of the Cathode Ray Tube is coated with what material?
(A) No coating
(B) Fluorescent powder
(C) Phosphorus
(D) None of the above
9. . Which among the following is a part of the Cathode Ray Tube?
(A) Control Electrode
(B) Electron Gun
(C) Focusing System
(D) All of the Above
10. . CRT stands for,
(A) Cathode Random Tunnel
(B) Cathode Ray Tube
(C) Cathode Random Tube
(D) Cathode Ray Tunnel