Examkin

Soru

Zorluk: OrtaPhotoelectric Effect and Work Function

Ultraviolet radiation of fixed frequency ff, which exceeds the threshold frequency f0f_0 of a zinc emitter plate, causes photoelectron emission. If the intensity of the incident radiation is multiplied by two without altering its frequency, what is the effect on the maximum kinetic energy of the photoelectrons and the emission current?

  1. The maximum kinetic energy is unchanged, but the emission current is doubled.Cevap
  2. B
    The maximum kinetic energy is doubled, and the emission current is also doubled.
  3. C
    The maximum kinetic energy is doubled, while the emission current remains unchanged.
  4. D
    The maximum kinetic energy and emission current both remain unchanged.

Cevap

The maximum kinetic energy is unchanged, but the emission current is doubled.
In the photoelectric effect, the maximum kinetic energy of emitted electrons (Kmax=hf−W0K_{\text{max}} = hf - W_0) depends only on the frequency of the incident radiation and the work function of the metal. Changing light intensity changes only the number of photons arriving per second, which doubles the rate of photoelectron emission and hence doubles the photoelectric current while leaving maximum kinetic energy unchanged.

Adım Adım Çözüm

1
Analyze the dependence of maximum kinetic energy on radiation parameters using Einstein's photoelectric equation.
Kmax=hf−W0K_{\text{max}} = hf - W_0. Since frequency ff and work function W0W_0 remain constant, KmaxK_{\text{max}} remains unchanged.
Individual photon energy is determined strictly by frequency (E=hfE = hf). Intensity does not alter individual photon energy.
2
Analyze the relationship between light intensity and photoelectric current.
Intensity II is directly proportional to the number of incident photons per second (NN). Since one photon liberates one electron, doubling intensity doubles the photoelectron emission rate, thereby doubling the photoelectric current.
Photoelectric current measures the rate of charge emission, which depends directly on photon flux.

Anahtar Kavram

Independence of photoelectron kinetic energy from light intensity
Bu soruyu puanla

Konular

Photoelectric Effect and Work Function

Bu konudan daha fazla soru