Usually the unit of measurement of velocity is meters per second or m/s
The wavelength of the light beam required to turn back all the ejected electrons is 497 nm which is option (b).
- Work function is a material property defined as the minimum amount of energy required to infinitely remove electrons from the surface of a particular solid.
- The potential difference required to support all emitted electrons is called the stopping potential which is given by
.....(1) - where
is the stopping potential and e is the charge of the electron given by
.
It is given that work function (Ф) of monochromatic light is 2.50 eV.
Einstein photoelectric equation is given by:
....(2)
where K.E(max) is the maximum kinetic energy.
Substituting (1) into (2) , we get

As we know that
....(3)
where Speed of light,
and Planck's constant , 
From equation (3) , we get

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Answer:
Power
Explanation:
Power is defined as the rate of doing work with reference to the time spent and the formula is force multiplied by velocity.
In this case, if two people lift identical stacks of books the same distance and one person does the job twice as fast, then it means the velocity in the case is doubled which will also lead to an increase in the Power .
<span>division of Earth's history into time units based largely on the types of life-forms that lived only during certain periods.</span>