Question

Consider a laser pointer that emits red light with wavelength 650 nm. This light is used for a photoelectric effect experiment where the anode in the evacuated glass tube is made up of a material that has work function equal to 1 eV.

[1] What is the energy of an individual photon that comes out of the laser pointer?

[2] What is the maximum kinetic energy of an emitted electron?

Answer #1

1) The energy of a photon is given by the equation E = hc/λ

where E is the energy, Planck's constant h = 6.626 x
10^{-34} Js, c = 3.00 x 10^{8} m/s (speed of
light), λ is the wavelength of the light (in metres).

So in your case, λ = 650 x 10^{-9} m, so the energy of
one photon is:

E = (6.626 x 10^{-34} 3.00 x
10^{8})/650 x 10^{-9} = 3.058
10^{-}^{19} J = 1.91 eV

2) According to photoelectric effect,

max. K.E of electron = energy of incident photon - work
function

max. K.E of electron = 1.91 - 1 = 0.91 eV

A red laser pointer emits light with wavelength 488 nm. If the
laser emits 7.5 x 10–4 J of energy per second, how many photons per
second are emitted from the laser?

Light of wavelength 235 nm is incident on Magnesium in a
photoelectric effect experiment. The work function of Magnesium is
3.68 eV.
(a) What is the maximum kinetic energy of the emitted electrons,
in eV?
(b)What is the maximum velocity of the emitted electrons, in
m/s?
(c) What is the stopping potential, in Volts, that results in no
collected photoelectrons?
(d) Light of wavelength 235 nm is now incident on lead (work
function 5.40 eV). What is the maximum kinetic...

The hydrogen emission spectrum produces light at 430 nm (blue),
480 nm (blue-green) and 650 nm (red).
Find the energy in Joules and then in eV for a photon at each of
these wavelengths:
430 nm:
480 nm:
650 nm:
A metal surface has a work function (W0) of 2.7
eV. Of the three wavelengths of light in the hydrogen
spectrum, which would be able to release electrons from the metal
surface?
Calculate the kinetic energy in eV if any, of...

a) A photon of wavelength 43 nm is incident upon a metal in a
photoelectric apparatus. A stopping voltage of 21 V was obtained.
What is the threshold frequency of the metal? (format of a.b x
10cdHz)
b) Light with a frequency of 5.00 x 1014 Hz
illuminates a photoelectric surface that has a work function of
2.10 x 10-19 J. What is the maximum kinetic energy of
the emitted photoelectrons? (format of a.bc x 10-de J
)
c) Light...

The “electric eyes” used to open doors automatically are based
on the photoelectric effect. The metal surface inside the “eye” [an
evacuated glass chamber containing the surface (cathode) and a
photocurrent collector (anode)] continuously provides current until
the light beam that actuates it is interrupted.
a. What is the maximum kinetic energy of photoelectrons produced
by a mercury vapor lamp which emits 436 nm violet light causing the
actuation of an electric eye of work function 2.1 eV?
b. What...

The YAG Laser in the Laser Laboratory is a pulsed laser that
emits infrared light of wavelength 1064 nm at a frequency of 10 Hz.
Suppose that one pulse from the YAG Laser has an average energy of
1.2 J and lasts for a time of 14 ns. What is the energy (in
eV) of one photon of this laser light?
How many photons are emitted in one
pulse from the YAG Laser?
What is the power output (in W)...

2a) When a metal surface is illuminated by light of wavelength
310 nm, the
measured maximum kinetic energy of the emitted electrons is 0.50
eV. Calculate the
metal plate’s work function φ in units of eV.
b) In the rest frame of an ejected electron from the photoelectric
experiment in part a),
an incident γ-ray with an energy of 0.25 MeV interacts with the
electron. Following
the collision, the γ-ray has a final energy of 0.1 MeV. Calculate
the angle...

A red laser emits a pulse of light every 10 ms. If the laser
operates at a wavelength of 695 nm and 50 W, calculate the number
of photons emitted during a pulse. (1 W = 1 J/s).

A photon with a wavelength of 2.47 nm strikes a surface and
emits an electron with kinetic energy of 228 eV (electron volts).
What is the binding energy of the electron in J? Round your answer
to 2 sig figs. 1 electron volt = 1.602 x 10-19 J

Consider a beam of light with a wavelength λ = 403-nm incident
onto a metal surface, which can be Li, Be or Hg. The work functions
of these metals are 2.30-eV, 3.90-eV and 4.50-eV respectively. For
the metal that exhibits the photoelectric effect find the maximum
kinetic energy of the photoelectrons.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 4 minutes ago

asked 8 minutes ago

asked 17 minutes ago

asked 21 minutes ago

asked 28 minutes ago

asked 32 minutes ago

asked 33 minutes ago

asked 39 minutes ago

asked 40 minutes ago

asked 47 minutes ago

asked 54 minutes ago