Read the following statements about the photoelectric effect: 1. The kinetic energy of emitted photoelectrons increases with increasing intensity of incident light. 2. The photoelectric effect demonstrates the particle nature of light. 3. There is a threshold frequency below which no photoemission occurs, regardless of light intensity. Which of the above statements are correct?
2 and 3 only
Apply Einstein's photoelectric equation: \(KE_{max} = h\nu - \phi\), where \(h\nu\) is the photon energy and \(\phi\) is the work function.
Statement 1 (Wrong): The kinetic energy of emitted photoelectrons depends on the frequency of the incident light, not its intensity. Increasing intensity increases the number of emitted electrons, but not their kinetic energy.
Statement 2 (Correct): The photoelectric effect cannot be explained by the wave theory of light. Einstein's explanation in 1905 (using photons / quanta) demonstrated the particle nature of light.
Statement 3 (Correct): Photoemission occurs only if \(\nu \ge \nu_0\) (the threshold frequency, where \(h\nu_0 = \phi\)). Below this frequency, no electrons are emitted regardless of intensity.
Hence statements 2 and 3 only are correct.
Important Questions from Dual Nature: Photon and Matter Waves
The wavelength of the matter waves associated with a fast moving sub-atomic particle depends upon
(i) charge
(ii) mass
(iii) velocity
(iv) spin state and
(v) momentum
The correct factors are
In a photoelectric experiment, both sodium (work function = 2.3 eV) and tungsten (work function = 4.5 eV) metals are illuminated by an ultraviolet light of same wavelength. If the stopping potential for tungsten is measured to be 1.8 V, then the value of the stopping potential for sodium will be
Schrodinger wave equation can be written as:
Energy of a photon of wavelength 5890A° emitted by sodium vapour lamp is
The experimental evidence that the electron exhibits wave-like characteristics was first provided by:
