If the maximum kinetic energy of emitted electrons in photoelectric effect is 2ev, the stopping potential will be

[ "article:topic", "authorname:openstax", "cut-off frequency", "cut-off wavelength", "energy of a photon", "photocurrent", "Photoelectric effect", "photoelectrode", "photoelectron", "photon", "quantum phenomenon", "stopping potential", "work function", "license:ccby", "showtoc:no", "program:openstax", "licenseversion:40", "source@https://openstax.org/details/books/university-physics-volume-3" ] Learning Objectives By the end of this section you will be able to: • Describe physical characteristics of the photoelectric effect • Explain why the photoelectric effect cannot be explained by classical physics • Describe how Einstein’s idea of a particle of radiation explains the photoelectric effect When a metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength (or equivalently, above a threshold frequency), the incident radiation is absorbed and the exposed surface emits electrons. This phenomenon is known as the photoelectric effect. Electrons that are emitted in this process are called photoelectrons. The experimental setup to study the photoelectric effect is shown schematically in Figure \(\PageIndex\): An experimental setup to study the photoelectric effect. The anode and cathode are enclosed in an evacuated glass tube. The voltmeter measures the electric potential difference between the electrodes, and the ammeter measures the photocurrent. The incident radiation is monochromatic. When the target material is not exposed to radiatio...

Emitted electrons and kinetic energy When an electron is ejected from a metal surface it has kinetic energy. The amount of kinetic energy the electron has depends on the difference between the energy of the photon and the work function of the metal. The kinetic energy of the electron is equal to the energy of the photon minus the work function of the metal. This is shown by the equation: \[E_)\]

Learning Objectives By the end of this section, you will be able to: • Describe physical characteristics of the photoelectric effect • Explain why the photoelectric effect cannot be explained by classical physics • Describe how Einstein’s idea of a particle of radiation explains the photoelectric effect When a metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength (or equivalently, above a threshold frequency), the incident radiation is absorbed and the exposed surface emits electrons. This phenomenon is known as the photoelectric effect. Electrons that are emitted in this process are called photoelectrons. The experimental setup to study the photoelectric effect is shown schematically in photoelectrode. Photoelectrons are collected at the anode, which is kept at a higher potential with respect to the cathode. The potential difference between the electrodes can be increased or decreased, or its polarity can be reversed. The electrodes are enclosed in an evacuated glass tube so that photoelectrons do not lose their kinetic energy on collisions with air molecules in the space between electrodes. When the target material is not exposed to radiation, no current is registered in this circuit because the circuit is broken (note, there is a gap between the electrodes). But when the target material is connected to the negative terminal of a battery and exposed to radiation, a current is registered in this circuit; this current is called t...

Statement-1 : When ultraviolet light is incident on a photocell, its stopping potential is V 0 ​ and the maximum kinetic energy of the photoelectrons is K m a x ​ . When the ultraviolet light is replaced by X-rays, both V 0 ​ and K m a x ​ increase. Statement-2 : photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light.

• The maximum kinetic energy of the emitted electrons in a photoelectric effect is 200 eV. If the work function of the metal is 25.0 eV, find the wavelength of the incident photons. • Compute the stopping potential if photons enter a photoelectric surface with wavelength 950 nm and if the threshold wavelength of the metal is 1280 nm.