REVISION FLASHCARDS

Question 1

Scale reading uncertainty

Answer 1

for analogue: ± ½ the smallest scale division
for digital: ± the smallest scale division

Question 2

Random uncertainty

Answer 2

Question 3

Systematic uncertainty

Answer 3

Systematic uncertainty is usually caused by a faulty piece of equipment, or a flaw in the procedure.
A systematic uncertainty will affect each result in the same way (either consistently too big or too small).

Question 4

Electric field

Answer 4

Electric field is a region of space in which a charged particle can experience a force without being in contact with another object.

Question 5

1 volt

Answer 5

1 volt is equivalent to 1 joule of energy supplied to each coulomb of charge (1 V = 1 J.C-1)

Question 6

EMF

Answer 6

EMF: the energy / number of joules supplied to each coulomb of charge by a cell.

Question 7

tpd

Answer 7

Terminal potential difference – the ‘useful’ voltage obtained from a cell when there is a current in the circuit (t.p.d. = I x R)

Question 8

Lost volts

Answer 8

Lost volts is the voltage across the internal resistance of the cell. (Lost volts = I x r)

Question 9

AC

Answer 9

AC – alternating current.
Current changes direction and instantaneous value with time.

Question 10

DC

Answer 10

DC – direct current.
Charge flows in one direction, from negative to positive.

Question 11

Capacitance

Answer 11

Capacitance is a measure of the amount of charge stored per volt.

Question 12

Photoelectric effect

Answer 12

The process by which excess electrons are ejected from the surface of a metal by radiation above a certain frequency.

Question 13

Threshold frequency

Answer 13

(in the photoelectric effect)
The minimum frequency of radiation required to eject electrons from the surface of a metal.

Question 14

Work function

Answer 14

(in the photoelectric effect)
The minimum energy of a photon required for a particular metal to eject excess electrons from its surface.

Question 15

Constructive interference

Answer 15

When the waves from two sources meet in phase.

Question 16

Destructive interference

Answer 16

When the waves from two sources meet completely out-of-phase.

Question 17

Refractive index

Answer 17

The ratio of the speed of light in
a vacuum to the speed of light in the material.

n = v (vacuum) / v (material)

Question 18

Critical angle

Answer 18

The critical angle is the angle of incidence that results in an angle of refraction of 90 degrees to the normal.

Question 19

Irradiance

Answer 19

The power of radiation per square metre, incident on a surface. I = P/A

Question 20

Line spectrum

Answer 20

The spectrum produced by the electrons in a particular element falling to lower energy levels and emitting photons of light. Each ‘transition’ results in a different energy (and therefore frequency) of photon.

Question 21

Bohr model of the atom

Answer 21

Positively charged nucleus in centre (protons + neutrons).
Electrons orbiting in discrete energy levels.

Question 22

Hadron

Answer 22

A particle composed of quarks (e.g. proton, neutron)

Question 23

Baryon

Answer 23

A type of hadron – one which is composed of three quarks.

Question 24

Meson

Answer 24

A type of hadron – one which is composed of a quark-antiquark pair.

Question 25

Boson

Answer 25

A force-mediating particle (such as a photon, or gluon).

Question 26

Fermion

Answer 26

A fundamental particle (cannot be broken down into anything smaller) which is responsible for mass (could be one of the quarks: up, down, top, bottom, charm, strange; or one of the leptons: electron, electron neutrino, tau, tau neutrino, muon, muon neutrino )

Question 27

Anti-particle

Answer 27

An anti-particle is a particle that has the same mass but opposite charge from its corresponding particle. electron and positron up quark and anti-up quark electron neutrino and electron anti-neutrino

Question 28

Nuclear fission

Answer 28

When the nucleus of a particular atom becomes unstable and ‘splits’ into smaller fragments, releasing energy and usually neutrons.

Question 29

Nuclear fusion

Answer 29

When two smaller nuclei join together to form a larger nucleus. Energy is released during the process.

Question 30

The Principle of Conservation of Momentum

Answer 30

In the absence of external forces, the total momentum of before a collision (or explosion) is equal to the total momentum after the collision.

Question 31

Inelastic collision

Answer 31

The total kinetic energy of both objects after a collision does not equal the total kinetic energy of both objects before a collision.

Question 32

Impulse

Answer 32

The impulse of a force is equal to force multiplied by time (F x t) OR the change in momentum of an object involved in an interaction OR the area underneath a force-time graph

Question 33

Gravitational field strength

Answer 33

The force exerted per unit mass (by a gravitational field)