Fizik Definition
Fizik Definition
Fizik Definition
Chapter 5: LightRefraction
PHENOMENON where the direction of light is changed when it crosses theboundary between
two materials of different optical densities as a result of achange in the velocity of light.
Apparent depth
d , DISTANCE of the image from the surface of water (or the boundary betweenthe two
mediums involved)
Real depth,
D ,DISTANCE of the object from the surface of the water (or the boundarybetween the two
mediums involved)
Total internalreflection
TOTAL REFLECTION of a beam of light at the boundary of two mediums, whenthe angle of
incidence in the optically denser medium exceeds a specific criticalangle
Critical angle
GREATEST ANGLE OF INCIDENCE in the optically denser medium for which theangle of
refraction, r = 90°
Power of lens
MEASURE OF ITS ABILITY to converge or diverge an incident beam of light
PRINCIPLELaws of Reflection
-the angle of incidence, i, is equal to the angle of reflection, r (i = r)
-the incident ray, normal and reflected ray will all lie in the same plane
Law of Refraction
-The incident ray and the refracted ray are on the opposite sides of thenormal at the point of
incidence, all three lie in the same plane
-Obey snell’s law
Snell’s Law
The value of sin i/sin r is a constant.
IMAGE CHARACTERISTICS
Virtual
an image which cannot be projected (focused) onto a screen
Real
an image which can be projected (focused) onto a screen
Laterally inverted
an image which left and right are interchanged
Upright
an image which in vertical position
Diminished
image formed is smaller than the object
Magnified
image formed is larger than the object
Chapter 1 – WavesWaves
A TYPE OF DISTURBANCE produced by an oscillating or vibrating motion in which a point or body moves
back and forth along a line about a fixed central point produces waves.
Wavefront
LINE OR PLANE on which the vibrations of every points are in phase and are at the same
distance from the source of the wave.
In phase =
same direction, same displacemen
Transverse Wave
WAVE in which the vibration of particles in the medium is
perpendicular
to thedirection of propagation of the wave(water waves, light waves, electromagnetic waves)
Longitudinal Wave
WAVE in which the vibration of particles in the medium is
parallel to
the direction of propagation of the wave(sound waves, ultrasound)
Amplitude
MAXIMUM DISPLACEMENT form its equilibrium positionMEASURE of height of the wave crest or
depth of the wave trough.
Period
TIME TAKEN to complete an oscillation, from one extreme point to the other and backto the
same position.
Frequency
NUMBER OF COMPLETE OSCILLATIONS made by a vibrating system in one second
Wavelength, λ
DISTANCE between
successive points
of the same phase in a wave
Damping
DECREASE in the amplitude of an oscillating system is called damping.(Internal damping:
extension and compression of moleculesExternal damping: frictional force/ air resistance)a ↓ ; f =
Resonance
Resonance occurs when a system is made to oscillate at a frequency equivalent to its
natural frequency
by an external force. The resonating system oscillates at itsmaximum amplitude.
Natural frequency
FUNDAMENTAL FREQUENCY of which an object vibrates. It is the frequency of a
systemwhich oscillates freely without external force
Reflection of wave
Reflection of wave occurs when a wave strike an obstacledirection ≠ ; f = ; a = ; λ =
Refraction of wave
Refraction of wave occurs when a wave travel from one medium to anotherf = ; v ≠ ; λ ≠ ;
direction ≠
Diffraction of waves
PHENOMENON in which waves spread out as they passed through an aperture or rounda small
circlef = ; λ = ; speed = ; v ≠ ; direction ≠
Interference ofwaves
SUPERPOSITION of two waves originating from two
coherent
sourcescoherent =
same frequency, amplitude and in phase
Constructiveinterference
Constructive interference occurs when the both crests or both troughs of both wavescoincide
to produce a wave with crests and troughs of maximum amplitude
Destructiveinterference
Destructive interference occurs when the crest of one wave coincides with the troughof the
other wave, thus cancelling each other with the result that the resultantamplitude is zero
Antinode
POINT where constructive interference occurs.
Node
POINT where destructive interference occurs.
Electromagneticwaves
PROPAGATING WAVES in space with
electric
and
magnetic
components. Thesecomponents oscillate at right angles to each other and to the direction of
propagationof wave.
Monochromaticlight
LIGHT with only one wavelength and colour
PRINCIPLEPrinciple ofsuperposition
Principle of superposition states that at any instant, the wave displacement of thecombined
motion of any number of
interacting
waves at a point is the sum of thedisplacements of all the
components
waves at that point
Chapter 2 – ElectricityCharge, Q
WORK DONE to move a unit of voltage in a circuit
Current, I
RATE of flow of charge
Potentialdifference, V
WORK DONE in moving one coulomb of charge from one point to another in an electric field
Electric field
A FIELD in which electric charge experiences an electric forceA FIELD in which electric force
acts in a particle with electric charge
Circuit
CLOSED LOOP through which charge can continuously flow
Resistance, R
RATIO of the potential difference across the conductor to the current flowing through
itMEASURE of the ability of the conductor to resist the flow of an electric current through it
Superconductor
CONDUCTOR in which its resistance will suddenly become zero when it is cooled below acertain
temperature called the critical temperature
Electromotiveforce (e.m.f.)
TOTAL ENERGY supplied by a cell to move a unit of electrical charge from one terminal
to theother through the cell and the external circuit
Power rating
RATE at which it consumes electrical energy.
PRINCIPLEOhm’s Law
Ohm’s law states that the electric current,
I
flowing through a conductor is directlyproportional to the potential difference across the
ends of conductor, if temperature and otherphysical conditions remain constant. That is,
V directly proportional to I .
Chapter 3 – ElectromagnetismElectromagnet
DEVICE in which magnetism is produced by an electric currentTEMPORARY MAGNET which
acts as a magnet when the current is switched on and ceasesto be a magnet when the current is
switched off
Magnetic field
REGION in which a magnetic material experiences a force as the result of a magnet
or acurrent-carrying conductor
Radial field
MAGNETIC FIELD with the field lines pointing towards or away from the centre of a circle.
Electromagneticinduction
PRODUCTION of an electric current by a changing magnetic field (conductor cuts across
amagnetic flux –OR– a change of magnetic flux linkage with a coil)
Root mean squarecurrent/ voltage
VALUE of a steady current/ voltage, which would produce the same heating effect in
a givenresistor.
Transformer
EQUIPMENT to raise or lower the potential difference of an
alternating current
supply
PRINCIPLEFaraday’s Law
The magnitude of the induced electromotive force (e.m.f.) is directly proportional to therate of
change of magnetic flux linkage with the solenoid or the rate at which a conductorcuts through
the magnetic flux.
Lenz’s Law
Lenz’s law states that an induced electric current always flows in such a direction so as tooppose
the change (or motion) producing it
Chapter 4 – ElectronicsThermoionicemission
EMISSION of electrons from hot metal surface
Work function
MINIMUM ENERGY required to eject electrons from surface
Cathode ray
Fast moving ELECTRONS travel in a straight line in vacuum
Cathode rayoscilloscope
measuring and testing INSTRUMENT used in study of electricity and electronics
ConductorSemiconductorInsulator
MATERIAL which allows current to flow thorugh themMATERIAL whose resistance is
between good conductor and insulatorMATERIAL which does not conduct electric current
Junction voltage
POTENTIAL DIFFERENCE acting from n-type to p-type material of a diode across
the depletionlayer
Rectification
CONVERSION of a.c. to d.c. by diode
Smoothing
PROCESS where output is smoothed by connecting a capacitor across load that acts as
areservoir and maintains potential difference across load
Logic gates
ELECTRONIC SWITCHES with one or more inputs and one output
Chapter 5 – RadioactivityAtom
An atom consists of a nucleus which is made up of protons and neutrons, withelectrons orbiting
the nucleus.
Nuclide
TYPE of nucleus with particular proton number and nucleon number
Proton number
NUMBER of protons in the nucleus of an atom
Nucleon number
NUMBER of protons and neutrons in an atom
Isotopes
ATOMS of an element which have the same proton number but different nucleonnumber(similar
chemical properties but differs in physical properties)
Radioactivity
SPONTANEOUS DISINTEGRATION of
unstable
nucleus into a more
stable
nucleuswith the emission of energetic particles or protons
Radioactive decay
PROCESS where an unstable nucleus becomes a more stable nucleus by emittingradiations
Radioisotope
ISOTOPE that has unstable nucleus that tends to undergo radioactive decay
Half life
TIME TAKEN for the activity of atoms to fall to half its original valueTIME TAKEN for half
the atoms in a given sample to decay
Nuclear fission
PROCESS involving the splitting of a heavy nucleus into two nuclei of roughly equalmass and
shooting out several neutrons at the same time.
Nuclear fusion
PROCESS involving the fusion of two or more small and light nuclei come togetherto form a
heavier nucleus.
PRINCIPLEEinstein’s Principle ofMass-Energy Conservation
The change of energy is linked to the change of mass by the equation
E=mc2