Which of the following is correct for cathode rays in discharge tube?A Independent of the nature of the cathode B Independent of the nature of the gas C Deflection is observed in presence of electric and magnetic field D All of these

The correct answer is D: All of these.

Here's why:

A: Independent of the nature of the cathode - This is correct because cathode rays are streams of electrons that are emitted from the cathode (negative electrode) in a discharge tube. The nature of the cathode does not affect the production of these rays.

B: Independent of the nature of the gas - This is also correct. The type of gas present in the discharge tube does not affect the production of cathode rays. The gas is ionized during the process, but it's the cathode that produces the electrons (cathode rays).

C: Deflection is observed in presence of electric and magnetic field - This is correct as well. Cathode rays, being composed of electrons, are deflected by both electric and magnetic fields. This is due to the charge and mass of the electrons.

So, all of the statements A, B, and C are correct about cathode rays in a discharge tube.

The correct answer is D: All of these.

Here's why:

A: Independent of the nature of the cathode - This is correct because cathode rays are produced by the ionization of any metal, so their production does not depend on the type of metal used as the cathode.

B: Independent of the nature of the gas - This is also correct. The production of cathode rays does not depend on the type of gas used in the discharge tube.

C: Deflection is observed in presence of electric and magnetic field - This is correct as well. Cathode rays are composed of electrons, which are negatively charged particles. Therefore, they are deflected by electric and magnetic fields.

So, all of the statements A, B, and C are correct, which makes D the correct answer.