False. light bounces off the object giving it its colors :)
If the light of wavelength 700 nm strikes such a photocathode the maximum kinetic energy, in eV, of the emitted electrons is 0.558 eV.
so - $KE_{max} = hc/lembda} work
threshold when KE = 0
hc/lambda = work = 1240/900=1.38 eV
b) Kemax = hc/lambda - work = 1240/640 -1.38=0.558 eV
What is photocathode?
- A photocathode electrolyte interface can be used in a photoelectrolysis cell as the primary light-harvesting junction (in conjunction with an appropriate electrochemical anode) or as an optically complementary photoactive half-cell in a tandem photoelectrode photoelectrolysis cell (Hamnett, 1982; Kocha et al, 1994).
- In the case of the former, the electrode should ideally harvest photon energy across the majority of the solar spectrum in order to achieve the highest energy conversion efficiency possible.
- In the latter case, however, the photocathode may only be active in a specific band of the solar spectrum in order to generate a cathodic photocurrent sufficient to match the current generated in the photoanodic half-cell.
To learn more about Photocathode from the given link:
brainly.com/question/9861585
#SPJ4
Answer:
0.8976 seconds
Explanation:
The period of oscillation for the simple harmonic motion can be found using the formula ...
T = 2π√(d/g)
where d is the displacement of the spring due to the attached weight, and g is the acceleration due to gravity.
__
For d = 0.20 meters, the period is ...
T = 2π√(0.20/9.8) ≈ 0.8976 . . . . seconds
_____
<em>Additional comment</em>
The formula for the oscillator period is usually seen as ...
T = 2π√(m/k)
where m is the mass in the system and k is the spring constant. The value of the spring constant is calculated from ...
k = mg/d
Using that in the formula, we find it simplifies to ...

Explanation:
The nucleus of an atom can be modeled as several protons and neutrons closely packed together.
Mass of the particle, 
Radius of the particle, 
(a) The density of the nucleus of an atom is given by mass per unit area of the particle. Mathematically, it is given by :
, V is the volume of the particle



So, the density of the nucleus of an atom is
.
(b) Density of iron, 
Taking ratio of the density of nucleus of an atom and the density of iron as :



So, the density of the nucleus of an atom is
times greater than the density of iron. Hence, this is the required solution.
Answer:
the energy of the photons is greater than the work function of the zinc oxide.
h f> = Ф
Explanation:
In this experiment on the photoelectric effect, it is explained by the Einstein relation that considers the light beam formed by discrete energy packages.
K_max = h f - Ф
in the exercise phase, they indicate that different wavelengths can inject electrons, so the energy of the photons is greater than the work function of the zinc oxide.
h f > = Ф