Unit 1

Question 0

Strong Force only affects what classification of particle?

Answer 0

Hadrons

Question 1

What is Pair Production?

Answer 1

When a gamma ray photon has enough energy to produce enough mass to form a particle-antiparticle pair.

(Usually and electron-positron pair)

Question 2

What is meant by an Excited atom?

Answer 2

An electron is at a higher level that ground state

Question 3

What is the quark structure of a meson?

Answer 3

Quark-Antiquark pair

Question 4

Which is the only stable Baryon?

Answer 4

The Proton

Question 5

What does a neutron decay into? (Beta-plus decay)

Answer 5

Proton —> Neutron + Positron + Electron-neutrino

Question 6

What is the quark composition of a Proton?

Answer 6

UUD

Question 7

What is the quark composition of a Neutron?

Answer 7

UDD

Question 8

Describe the process to get visible light from a fluorescent tube

Answer 8

Fluorescent tubes contain mercury vapour and when an electric current flows through the tube electrons collide with mercury atoms raising the electrons to a higher state in the mercury atom. When this electron returns to it’s regular state there is a photon emitted. However these photons are in the ULTRA VIOLET spectrum so a coating on the tube absorbs the photon and emits another photon with less energy so a shorter wavelength and in the visible light spectrum.

Question 9

What is Annihilation?

Answer 9

When a particle and it’s antiparticle meet and their mass’ are converted back to energy. The formation of 2 photons.

Question 10

Everything decays under what interaction?

Answer 10

Weak Interaction

Question 11

Beta-plus decay?

Answer 11

Proton —> Neutron + Positron + Electron-neutrino

Question 12

What 4 properties must be conserved in particle interactions?

Answer 12

Charge
Baryon number
Strangeness
Lepton number

Question 13

Beta-minus decay?

Answer 13

Neutron —> Proton + Electron + Anti-Electron-neutrino

Question 14

When a neutron decays into a proton what quark changes?

Answer 14

D —> U

Question 15

In a PARALLEL circuit, what happens to current and voltage?

Answer 15

Current splits at each branch and voltage is the same across each branch

Question 16

In a SERIES circuit what happens to current and voltage?

Answer 16

Current is the same and voltage splits between each component

Question 17

What is EMF?

Answer 17

Electromotive force - the amount of electrical a battery produces

Question 18

How can we work out the average of an AC Current?

Answer 18

Root Mean Square current.

Divide the peak current by the square root of 2

Question 19

What is the exchange particle for the Strong Force and what particles are affected by this interaction?

Answer 19

Exchange particle = gluon (glue is strong??)

It affects Hadrons only.

Question 20

What is the exchange particle for the Weak Force and what particles are affected by this interaction?

Answer 20

Exchange particle = W Boson (W for weak)

All particles are affected so most interactions are under weak interaction

Question 21

What is the exchange particle for the Electromagnetic Force and what particles are affected by this interaction?

Answer 21

Exchange particle = photon (electromagnetic spectrum = light = photon??)

This only affects charged particles