Quanta & waves

Question 1

Waves displaying particle behaviour

Answer 1

Photoelectric effect

Compton scattering- collision between photon and electron

Question 2

Particles displaying wave behaviour

Answer 2

Electron diffraction - electrons can be shown to diffract (through Crystal lattice of a solid acting as grating) if the de Broglie wavelength is similar to grating/lattice spacing

Interference if more than one grating

Question 3

Heisenbergs uncertainty principle

Answer 3

It is impossible to determine accurately the exact position and momentum of a quantum particle simultaneously

Question 4

Quantum tunnelling

Answer 4

Their is a finite possibility that an object (“particle”) trapped behind a barrier without enough energy to overcome the barrier may appear on the other side of it

Question 5

Helical motion

Answer 5

Perpendicular component of velocity results in circular motion

Parallel component of velocity’s constant cause lung it to move forward

Question 6

Simple harmonic motion

Answer 6

An oscillation where an object repeats a motion about an equilibrium position under the influence of an unbalanced force which is:

• always directed towards equilibrium position (^opposite to displacement)
• proportional to displacement from equilibrium position

Question 7

Comic rays

Answer 7

• 89% protons
• 9%alpha particles
• 1% carbon, oxygen, and nitrogen nuclei
• remainder electron and gamma rays

Question 8

Solar wind

Answer 8

A stream of charged particles which escaped from the upper atmosphere of the sun

It moves at a high speed and consists of mainly electrons, protons and alpha particles in the state of plasma.

Question 9

Damping

Answer 9

Damping of a system describes the rate at which energy is being lost or the rate at which the amplitude is decreasing

Damping can occur naturally due to friction or can be purposeful achieved by submerging system in a viscous fluid

Question 10

Stationary waves

Answer 10

Formed by the interference of two waves of the same frequency and amplitude travelling in opposite direction.

N= nodes (points of zero disturbance)
A= anti-nodes (points of maximum disturbance)

Question 11

Interference

Answer 11

Produced when “coherent” (constant phase difference/relationship) waves overlap.

Question 12

Phase change on reflection

Answer 12

A phase change of pi occurs when light reflects off a medium with a higher refractive index (“more optically dense”)

Question 13

Polarisation

Answer 13

Plane polarised light oscillates in ONE plane only

Question 14

Brewster angle (ip) (polarisation by reflection

Answer 14

Angle of in Incidence which causes reflected light to be fully polarised