Which of the following is not true with respect to cathode rays?

Positive rays consist of

Cathode rays consist of

$A$ metal plate gets heated when cathode rays strike against it due to:

Who evaluated the mass of the electron indirectly with the help of its charge?

$A$ beam of cathode rays is subjected to crossed electric $(E)$ and magnetic fields $(B).$ The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by (where $V$ is the potential difference between cathode and anode):