28 - Quantum physics

Question 1

Deinf photoelectric effect

Answer 1

an interaction between a photon and an electron in a metal, in which the electron is removed from the surface of the metal

Question 2

Define photon

Answer 2

a quantum of electromagnetic energy

Question 3

Define Planck constant

Answer 3

a fundamental constant that links the energy of a photon E and its frequency f
E = hf

Question 4

Planck constant equation

Answer 4

E = hf = hc/λ

Question 5

Define electronvolt

Answer 5

the energy gained by an electron travelling through a potential difference of 1 volt

Question 6

Define threshold voltage

Answer 6

the minimum forward bias voltage across a light-emmiting diode when it starts to conduct and emit light

Question 7

Define threshold frequency

Answer 7

the minimum frequency of the incident electromagnetic radiation that would eject electrons from the surface of a metal

Question 8

Define threshold wavelength

Answer 8

the longest wavelength of the incident electromagnetic radiation that would eject electrons from the surface of a metal

Question 9

Define work function energy

Answer 9

the minimum energy needed by an electron to free itself from the surface of a metal

Question 10

de Broglie wavelength equation

Answer 10

λ = h/p or λ = h/mv
p = momentum
mv = p