Question

Among the following, the correct statement about cathode ray discharge tube is

• A. the electrical discharge can only be observed at high pressure and at low voltage.
• B. in the absence of external electrical or magnetic field, cathode rays travel in straight lines.
• C. the characteristics of cathode rays depend upon the material of electrodes.
• D. the characteristics of cathode rays depend upon the gas present in the cathode ray tube

Answer 1

Answer: (B)

Cathode ray is observed only at low pressure and high voltage, which travel in straight line in the absence of electrical and magnetic fields. Characteristics of cathode rays are independent of the material of electrode or the gas present in the tube