The metal which has the highest work function among the following is:

Cathode rays are....

Which one of the following devices makes use of the electrons to strike certain substances to produce fluorescence?

How can the mass of an electron be obtained?

$A$ cathode emits $1.8 \times 10^{14}$ electrons per second when heated. When $400 \ V$ is applied to the anode,all the emitted electrons reach the anode. The charge on an electron is $1.6 \times 10^{-19} \ C$. The maximum anode current is ............ $\mu A$.

When subjected to a transverse electric field,cathode rays move