Who developed the hot cathode ray tube?
A. W. D. Coolidge
B. A. Cieszynski
C. H. R. Raper
D. O. Walkhoff
Answer:A
Who developed the hot cathode ray tube?
A. W. D. Coolidge B. A. Cieszynski C. H. R. Raper D. O. Walkhoff
Explanation: A) William David Coolidge developed the shockproof hot cathode tube while working for General Electric Company in 1913.