You have to do the math of each and see which one adds up to 66.5
Answer:
the second one i guess????
Explanation:
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:
C
Explanation:
they both have to be the same for both to not move
A point charge is located at the origin of a coordinate system. A positive charge is brought in from infinity to a point. The charges are at distance for given electrical potential energy is 3.34 x 10⁷ m.
<h3>What is electric potential energy?</h3>
The electric potential energy is the work done by a test charge to bring it from infinity to a particular location.
The electric potential energy is given by the relation,
V = kQ/r
where k = 9 x 10⁹ J.m/C ,Q = 3 x 10⁻⁹ C, V =8.09 × 10⁻⁷ J.
Substitute the values into the expression to get the distance between the charges.
8.09 × 10⁻⁷ = 9 x 10⁹ x 3 x 10⁻⁹ / r
r =3.34 x 10⁷ m
Thus, the distance between the charges will be 3.34 x 10⁷ m.
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