Quantum Physics

Question 1

The photoelectric effect

Answer 1

a process in which electrons are emitted from a metal surface when electromagnetic radiation of sufficiently high frequency is incident on the surface

Question 2

Photoelectron

Answer 2

an electron emitted from the surface of a material due to the incident electromagnetic radiation

Question 3

Stopping potential, V_s

Answer 3

The magnitude of the negative potential of the collector w.r.t the emitter which prevents most energetic photoelectrons from reaching the collector and hence resulting in zero photocurrent

Question 4

Photon

Answer 4

A quantum of electromagnetic energy

Question 5

Work Function energy

Answer 5

The minimum amount of energy necessary for an electron to escape from the surface of a material

Question 6

Threshold Frequency

Answer 6

The minimum frequency of electromagnetic radiation below which no emission of photoelectrons occurs

Question 7

Wave-Particle Duality

Answer 7

The theory where matter and waves have particle like and wave like characteristics

Question 8

De Broglie Wavelength

Answer 8

The wavelength associated with wave-like properties of a particle

Question 9

Heisenberg Uncertainty Principle

Answer 9

States that if a measurement of the position of a particle is made with uncertainty and a simultaneous measurement of its x-component of momentum is made with uncertainty, the product of the two uncertainties can never be smaller than h-bar/2

Question 10

Experimental observations that led to realisation of Wave-Particle Duality

Answer 10

(a) Existence of Threshold Frequency
(b) Max KE is independent of Intensity
(c) Insignificant Time Lag