# How do you use Planck's constant to determine frequency of a photon (given t frequency) or the energy (given the frequency)?

##### 1 Answer

Mar 18, 2017

#### Answer:

using *Planck - Einstein relation*

#### Explanation:

Using the equation E = h *v*

where

E is the energy

h is planks constant

*v* is frequency

If energy is given then frequency can be determined as

*v* = E/h

If frequency is given energy can be determined as

E = h *v*