When light is incident on a metal surface, electrons may
be ejected. The graph below shows the variation with frequency
f of the maximum kinetic energy MKE of the ejected electrons.When light is incident on a metal surface, electrons may
be ejected. The graph below shows the variation with frequency
f of the maximum kinetic energy MKE of the ejected electrons.
Which one of the graphs at right best shows the variation with frequency f of the maximum kinetic energy MKE of the ejected electrons if another surface with a lower threshold frequency is used?
Monochromatic light is incident on a metal surface and the ejected electrons
give rise to a current in the circuit. The maximum energy of the
ejected electrons is determined by applying a reverse ("stopping")
potential to reduce the current registered by the amp meter to
zero.
If the intensity of the incident light is gradually increased, the stopping potential required will....
a ... decrease.
b ... remain unchanged.
c ... increase continuously.
d ... increase to a limiting value.
The apparatus
sketched at right is used to measure the stopping potential
Vs for photoelectrons emitted from a metal
surface. Vs is measured for different frequencies
of light f, incident on the surface.
The broken line on the graph below, labeled R, shows the results obtained when the metal plate is zinc.
The zinc plate is replaced with another metal plate having a higher work function.
Which line on the graph would best represent the results obtained in this case?
a P
b Q
c R (no change)
d S
Electromagnetic radiation of a certain intensity is incident
on a metallic surface with a work function of 3 eV. Photoelectrons
are produced with a maximum kinetic energy of 1 eV. If the frequency
of the incident radiation is doubled, the maximum kinetic energy
of the photoelectrons will be....
a 2 eV
b 4 eV
c 5 eV
d 7 eV
When light is shone on to a metal surface electrons can
be ejected.
Which one of the graphs at right best shows the relationship between the maximum kinetic energy E of the ejected electrons and the frequency f of the incident light?
Which one of the graphs at right best shows how the maximum
kinetic energy of electrons emitted from the surface of a metal
varies with the wavelength of the light incident on the surface.