Which of the following statements is not correct about the characteristics of cathode rays?
(a) They start from the cathode and move towards the anode.
(b) They travel in straight line in the absence of an external electrical or magnetic field.
(c) Characteristics of cathode rays do not depend upon the material of electrodes in cathode ray tube.
(d) Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube.
The answer is the option (d)
Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube because we know that nature of the gas in the cathode rays and characteristics of the cathode rays have no bearing on the material of the electrodes.