Answer:
The frequency of the photon is
.
Explanation:
Given that,
Energy
We need to calculate the energy
Using relation of energy

Where,
= energy spacing


Put the value of h into the formula


Hence, The frequency of the photon is
.
Explanation:
In the given situation two forces are working. These are:
1) Electric force (acting in the downward direction) = qE
2) weight (acting in the downward direction) = mg
Therefore, work done by all the forces = change in kinetic energy
Hence,
It is known that the weight of electron is far less compared to electric force. Therefore, we can neglect the weight and the above equation will be as follows.

v = 
= 592999 m/s
Since, the electron is travelling downwards it means that it looses the potential energy.