What part of the CRT is tapered and lined with a conductive graphite coating?

• A. Aquadag
• B. Anode
• C. Cathode
• D. Screen

Answer: (A)

In a CRT, the inner surface of the tube, especially the tapered funnel area, is coated with a conductive graphite material called Aquadag. This coating provides a uniform electrical path along the inside of the tube, draining away static charges and helping to shape and stabilize the electric field that directs the electron beam. By keeping the potential along the inner surface well-defined, it aids beam focusing and deflection accuracy.

The other parts mentioned—anode, cathode, and screen—serve different roles. The anode is the high-voltage plate that attracts electrons; the cathode is the heated emitter of electrons; and the screen is the phosphor-coated front face that displays the image. None of these are the tapered, graphite-coated region described.