Physics Flashcards unit 1

Husein Essaji
Flashcards by Husein Essaji, updated more than 1 year ago
Husein Essaji
Created by Husein Essaji almost 6 years ago
27
1

Description

Flashcards on Physics Flashcards unit 1, created by Husein Essaji on 04/20/2015.

Resource summary

Question Answer
Explain pair production Photon interacts with atom Energy of photon used to create particle antiparticle pair
What roles do exchange particles play in interactions Transfer... Energy, momentum, force and sometimes charge
Electron Volt The kinetic energy gained by an electron when it is accelerated through a potential difference of 1 volt
Ohmic conductor V is directly proportional to I or Constant resistance
Principle property of superconductor A material which has zero resistance
Definition of an excited atom Orbital electron is at higher energy level than ground state
Difference between a Hadron and Lepton Leptons don't experience strong interaction Hadrons are not fundamental particles
What happens to positron produced by pair production Encounters another electron They annihilate Two high energy photons released
What is meant by Root mean square voltage The equivalent dc voltage that produces the same heating effect
Why does current of a lamp decrease after initial increase Resistance of filament increases because temperature of filament increases so current decreases
What happens to excess energy of photon in pair production Turns into kinetic energy of photon
Why are different energies of photons possible when electron de-excites The electron returns to lower energy level by a different route
Range of Strong Nuclear Force Attractive 3-4 femtometres Repulsive within 0.5 fm (femtometres = ^ -15 metres)
Define a Hadron Any particle or antiparticle that can interact though the strong interaction
Define emf Electrical energy per unit charge produced
When is max power delivered to load Load resistance = Source resistane
Work Function The work function of a metal is the minimum kinetic energy needed by an electron to escape the surface of a metal
Internal Resistance of battery The resistance of the material within the battery
Electron Capture Orbital electron interacts with proton in the nucleus via weak interaction to form a neutron and electron nuetrino
Explain why kinetic energy of emitted electron has a max value Electrons energy comes from absorption of photon. Energy required for electron varies as surface electrons require less energy. These electrons have max energy.
Explain why below a certain value electrons are not emitted Work function is the min energy needed to release an electron. Below a certain frequency, energy of photon is less than work function.
Why is the fact that there is no time delay is important Shows light must travel as photons which transfer energy in discrete packets
Explain the threshold frequency Threshold frequency is the min frequency for emission of electron. If below this value no emission even if intensity increased because the energy of photon is less than the work function.
Explain why an electron moves from ground state to n=2 in excitation Electron absorbs energy from incident electron. This ____ exact value is needed to make the transition
Why are electrons release from the metal surface Light consists of photons of energy hf. An electron at the surface of metal can only gain the energy of a single photon when it interacts with one. The work function of a metal is...Therefore elctron escapes metal if hf is greater than work function.
Why is it important to test by experiment a scientific theory If a reliable experiment does not support a hypothesis then the hypothesis must be changed
Internal resistance of a battery The resistance of the material within a battery
What is the terminal voltage Voltage across the circuit
Explain why emitted electrons have a range of KE Energy is required to leave surface of metal. Max KE is hf - work function. The deeper the electrons the more energy is used to get to the surface
Ground state When electrons in their lowest energy state/ most stable state
Excitation vs. Ionisation Both require the right amount of energy Excitation promotes electron to higher energy level Ionisation - electron receives enough energy to leave the atom
Why do photons of certain frequencies cause excitation in particular atom Electrons occupy discrete energy levels Need to absorb exact amount of energy to move to higher energy level Photons need to be of certain frequency All energy of photon is absorbed in 1 to 1 interaction
Explain what must happen in order for a new scientific theory to replace old one Theory makes prediction tested by other scientists
Measuring voltage using osciliscope Connect power supply to the input of the oscilloscope Time base switched off Adjust y gain until complete vertical line seen and measure. Convert by calibration.
Show full summary Hide full summary

Similar

B1.1.1 Diet and Exercise Flash Cards
Tom.Snow
AQA Physics P1 Quiz
Bella Statham
GCSE AQA Physics - Unit 3
James Jolliffe
GCSE AQA Physics 1 Energy & Efficiency
Lilac Potato
P2 Radioactivity and Stars
dfreeman
Biology Unit 1a - GCSE - AQA
RosettaStoneDecoded
AS Biology Unit 1
lilli.atkin
Cell Transport
Elena Cade
Psychology subject map
Jake Pickup
P2a revision (part 1)
juliasutton
Psychology A1
Ellie Hughes