Particles Section Flashcards
What is the definition for a potential difference of 1 Volt?
There is a potential difference of 1 Volt between two points if I joule of energy is required to move 1 coulomb of charge between the two points.
What force is carried by a photon?
Electromagnetic Force
What are the fingers representing in the right hand rule?
- First Finger - Field (Magnetic field)
- SeCond finger - Current
- THumb - Thrust (Movement)
Describe the electric field between a positive charge and a negative charge.
Field lines run from positive towards negative.
Describe the electric field around a positive charge.
Field lines away from the positive charge.
Give an example of a Baryon.
Proton
Neutron
What is meant by a Meson?
Mesons are made from 2 quarks.
They always consist of a quark and an antiquark pair.
What is a Boson?
Bosons are force carrying particles.
In the photoelectric effect, if the frequency of the incident radiation is increased what happens?
The electrons ejected will have more kinetic energy, if the frequency is greater than the threshold frequency.
What is beta (minus) decay?
Beta (minus) decay is when a neutron decays into a proton releasing an electron and an antineutrino.
Explain how a particle accelerator works.
- Acceleration of charged particles - use an electric field which causes particles to experience a force and accelerates them.
- Deflection of charged particles - magnetic fields are used to chage the direction of the moving charged particles.
- Collision of charged particles - against a fixed target or between two beams of particles.
What is the threshold frequency?
The minimum frequency of light required to eject an electron from a metal surface.
What represents a magnetic field going ‘into the page’?
A cross
What represents a magnetic field coming ‘out of the page’?
A dot
Name the four Bosons.
- Photons
- W and Z Bosons
- Gluons
- Gravitons
In a fusion reactor why are the high temperatures required a problem?
High temperature required to give the hydrogen atoms enough energy to overcome the electrical repulsion between the protons. This is difficult to contain as all materials would vaporise at this temperature.
What is meant by a Hadron?
Particles made from quarks
What is the Standard Model?
The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces.
What is a fundamental particle?
A fundamental particle is one that cannot be broken down into any sub particles.
What did beta decay provide the first evidence for?
The existence of neutrinos.
What is meant by fusion?
Fusion is when two small mass number nuclei combine to form a nucleus of a larger mass number.
Why were neutrinos suggested as an extra particle produced as a result of beta decay?
When beta decay occurs momentum and energy should be conserved. This was not happening if only the proton and beta particle were considered. There had to be another particle that carried the rest of the energy away.
When will a gold leaf electroscope discharge?
- It must be negatively charged
- It must have a zinc plate
- Ultraviolet light of a high enough frequency must be shone on the plate
- When the frequency of the ultraviolet light is above the threshold frequency
In physics what is meant by a field?
It is the region where an object experiences a force.