Photoelectric Effect

These flashcards cover key concepts related to the photoelectric effect, including definitions, principles, and implications of the phenomenon.

What is the photoelectric effect?

The photoelectric effect occurs when light shining onto a piece of metal causes electrons to be emitted.

What happens to electrons when light shines on a cathode?

Electrons gain enough energy to escape from the metal plate, forming a cloud of electrons that drifts towards the anode.

What is a cathode in the context of the photoelectric effect?

The cathode is the metal plate connected to the negative terminal of a battery.

What is the role of the anode in a photoelectric cell?

The anode is the metal plate connected to the positive terminal of the battery where emitted electrons drift.

How does the intensity of light affect the photoelectric effect?

Brighter light causes more electrons to be emitted, but does not increase the energy of individual electrons.

What determines the energy of emitted electrons in the photoelectric effect?

The energy of emitted electrons is determined by the frequency of the incoming light; higher frequency means greater energy.

What is the work function of a metal?

The work function is the minimum energy needed for an electron to be emitted from a metal.

How did Einstein explain the photoelectric effect?

Einstein proposed that light consists of fixed packets of energy called photons.

What happens with photons of different colors in the photoelectric effect?

Red light photons may not have enough energy to dislodge electrons, while blue light photons do.

What is the relationship between photon energy and frequency?

The energy of each photon is proportional to its frequency, expressed with the formula E = hf.

What is the formula relating energy, frequency, and wavelength?

E = hc / λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

What is the significance of the photoelectric effect in technology?

The photoelectric effect is used in devices like photoelectric cells for alarms and TV cameras.

What was the contemporary theory of light before the photoelectric effect was explained?

Classical electromagnetic wave theory modeled light as waves, likening them to water waves.

What is the implication of the photoelectric effect on the wave theory of light?

The photoelectric effect demonstrated that light also exhibits particle-like properties, leading to the development of quantum theory.