Question

Goldstein called the rays as canal rays because:
A. Rays were in the shape of a canal.
B. Rays couldn’t pass through holes in the cathode.
C. Rays pass through the holes or channels.
D. None of the above.

Answer 1

Hint:
E. Goldstein in 1886 discovered the presence of new radiations in a gas discharge and called them canal rays. Cathode rays move from anode to cathode.

Complete step by step solution:
Let us first look what was the experiment:
Basically in 1886 Eugen Goldstein noted that cathode ray tubes with perforated cathode emit a glow from the end of the tube near the cathode. E. Goldstein concluded from this experiment that in addition to the electrons, or cathode rays that travel from negatively charged cathode towards the positively charged anode, there is one more ray that travels in the opposite direction that is from positively charged anode towards the negatively charged cathode. And he named these rays as canal rays. And he named these rays canal rays because these rays used to pass through the channels, or holes, in the cathode.
So from this we can conclude that he named rays as canal rays because rays pass through the holes or channels in the cathode.

So the correct option of our question is 3rd.

Note:
It is to be noted that since the canal rays move in the opposite direction to the cathode rays hence canal rays must be having opposite charge from that of cathode rays. Since charge on cathode rays is negative so canal rays must be having positive charge.