Question

Assertion :

e/m ratio of anode rays is independent of nature of gas.

Reason :

All anode rays are protons.

• A. Both assertion and reason are correct and reason is the correct explanation of the assertion.
• B. Both assertion and reason are correct, but reason is not the correct explanation of the assertion.
• C. Assertion is correct, but reason is incorrect.
• D. Assertion is incorrect, but reason is correct.
• E. Both assertion and reason are incorrect.

Answer 1

The correct option is D Assertion is incorrect, but reason is correct.

In the case of anode rays, they are positively charged. Also, they are composed of ionised nuclei which vary from gas to gas in terms of atomic number and mass number. Thus, charge to mass ratio (e/m) of the positively charged ions changes as the number of nucleons changes in the nucleus of each gas can be different.

So, option E is correct.