The electrons in a cathode-ray tube are produced by?
A
heating a metal filament.
B
ionization of the air.
C
applying a magnetic field to the y-plates.
D
applying an electric field to the x-plates.
Verified Correct Answer: A.
Physical Principles & Numerical Solution
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #62310)