Final Exam Notes

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FINAL EXAM NOTES CHARGE AND FIELD MODELS Neutral objects can be pushed by a charged object Neutral objects can produce and electric field (dipole) FORCE TWO CHARGES EXERT ON EACH OTHER CAN BE THE SAME EVEN IF THEY HAVE DIFFERENT MAGNITUDES! Electric Field of point charge ̂ For electrostatics, field lines must begin and end on charges, so we may not just show field lines emanating from a point. ̂ ̂ In a plane of infinite charge the electric field on a point does not depend on the distance it is away from the plane. Electric Field of line of charge example next page.

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Transcript of Final Exam Notes

  • FINAL EXAM NOTES

    CHARGE AND FIELD MODELS

    Neutral objects can be pushed by a charged object

    Neutral objects can produce

    and electric field (dipole)

    FORCE TWO CHARGES EXERT

    ON EACH OTHER CAN BE THE

    SAME EVEN IF THEY HAVE

    DIFFERENT MAGNITUDES!

    Electric Field of point charge

    For electrostatics, field lines must

    begin and end on charges, so we may

    not just show field lines emanating

    from a point.

    In a plane of infinite charge

    the electric field on a point

    does not depend on the

    distance it is away from the

    plane.

    Electric Field of line of charge example next page.

  • Electric Field Strengths

    | |

    The field of a sphere of charge is the same as if it were all concentrated at the centre and modelled

    as a point charge.

    Dipoles

    In a uniform field

    o A point charge moves with constant acceleration

    o A dipole rotates until it is aligned with the field

    o NOTE DIPOLES HAVE NO NET FORCE IN UNIFORM FIELD BUT DO ROTATE FROM

    FIELD

    In a non-uniform field

    o Dipole moves toward region of

    higher field strength.

  • GAUSS LAW AND CONDUCTORS IN EQUILLIBRIUM If numerous closed shapes enclose a net charge, the flux through all shapes is equal.

    For Gauss Law to be effective need symmetry e.g. A surface over which the electric field is

    constant. SYMMETRY OF FIELD MUST MATCH SYMMETRY OF OBJECT.

    Note: flux is independent of radius and surface shape

  • In conductors the electric field inside is zero if in

    electrostatic equilibrium (no moving charges)

    In a conductor there is no net charge if there is no charge

    inside the object, meaning all charge is on the surface

    If there is a hole in an object then the flux inside this must

    be zero as seen in figure to the right.

    ELECTRIC POTENTIAL

    Think of electric field like gravity (long range force), in uniform

    field it can be said that

    Energy of a SYSTEM not just one particle is given as (Note: +ve for

    like charges, -ve for opposite)

    Electric potential can be thought of as stretch in spring (or hands)

    and the electric potential energy is the energy from this stretch

    This potential depends solely on the source and its charges

    Potential is the ability for something to happen (much like gravity)

    if we get a charge showing up this is when we consider electric

    potential energy (gravitational force).

    Potential is Volts, Electric Potential Energy is Joules

    Particles accelerate or deccelerate through potential

  • Electric potential inside a parallel plate capacitor (s is distance from negative plate)

    Not this potential is present inside all points of the capacitor

    NOTE AT NEGATIVE PLATE THERE CAN STILL BE CHARGE ONLY THE DIFFERENCE MATTERS

    Electric potential of a point charge (where q is the point and q is the other charge) can be

    modelled as

    Electric Potential of a charged sphere (R is radius of sphere and r is distance away from

    surface, V0 is potential sphere is charged too.)

    Electric potential obeys superposition such that

    Potential of the object is measured at z=0

  • ELECTRIC POTENTIAL EXAMPLES

  • POTENTIAL AND FIELD

    Chapter 30

    Electric potential and electric field are two different ways of thinking about how source

    charges affect space around them.

    Potential Energy is defined as work done by a force F on charge q as it moves from position

    i to position f.

    Can also think of potential energy as Vf=Vi (are under Es & s curve, see below)

    If force and direction of motion are orthogonal there is no work done on the object

    Seperation of charge creates potential difference.

    Battery potential can be seen as

    Finding the electric field from potential is extremely simple

  • Electrostatic force is CONSERVATIVE!

    The electric potential inside a parallel

    plate capacitor is from the

    negative plate. This means the closer

    the PROTON is to the negative plate

    the larger its potential energy is.

    Any two points inside a conductor will

    have the same potential.

    Electrostatic potential is known as the multiple of two

    charges so the two situations have the same potential

    (NOT ELECTRIC POTENTIAL!!!!!!!!).

    With two spheres the one with the larger radius will therefore have the lowest electric

    potential

    Potential spreads evenly over two objects, e.g. These

    two spheres have the same electric potential when the

    switch is closed.

    However the charge would be greater on Sphere 1 in

    this diagram, there is a larger radius and as they have

    the same potential we use the formula

    to

    realise it is a larger charge

    In contrast the electric field will be greater on Sphere 2,

    as it will have a greater surface charge density

  • Electric field is always perpendicular to the surface of a conductor in electrostatic equilibrium

    CAPACITORS

    When charged by at a battery the charge on capacitor slowly approaches battery charge

    This means that the positive capacitor plate has same charge as positive battery terminal

    and vice versa

    IN SERIES CAPACITORS: (

    )

    PARALLEL CAPACITORS:

    NOTE SUM OF ALL POTENTIAL DIFFERENCES AROUND A CLOSED PATH IS ZERO

    Current and Resistance

    Electron current is

    Electric field pushes the current

    Current is the rate at which charge flows

    Current per square metre of cross section or current density is given by

    Field strength in a wire is given by

    Electric field points in direction of current (From higher potential to lower potential).

  • Light bulbs will have the same brightness whether in series or parallel, only current differs.

    Magnetism

    Magnetic fields always try to oppose each other.

    Moving charges create magnetic field, using index to point to

    point, thumb as velocity of particle and palm as field direction we

    can say that.

    (

    )

    Superposition holds

    Can model a small segment of wire current as

    Can also model a coil of wire with N

    loops of ANY SHAPE as

    Interesting to note that a magnet and

    loop of current carrying wire create

    same magnetic field

    Magnets and current carrying wires just

    two different types of magnetism

  • Magnetic Dipole moment is simply

    Amperes Law is used to calculate the magnetic field created by wires and other objects as

    It should be noted that it is independent of shae of the curve

    Independent of where current passes through curve

    Depends only on total amount of current through area enclose by integration path

    CURVE MUST BE CLOSED

  • When considering a SOLENOID amperes law CHANGES to

    Magnetic field can exert force on current carrying wire and hence charge.

    ONLY MOVING CHARGES EXPERIENCE THIS FORCE

    FORCE IS ALWAYS PERPENDICULAR TO VELOCITY AND FIELD

    REVERSE ABOVE FORCES FOR NEGATIVE PARTICLE

    Can have something called cyclotron motion (see right) in which

  • As said before magnetic fields can have forces on current carrying wires

    Parallel wires also exert magnetic field on each other creating relationship

    Current loop is much like a magnetic dipole so it can be seen that they will act like magnets

    when near each other.

  • Torque is known to be force multiplied by distance from this we

    know that

    For loops to calculate torque we use the right hand rule where

    pointing finger is B and the field created by the loop (current

    carrying wire) is the thumb. In this example the torque is up and is

    out of the page.

    Electromagnetic Induction You can induce a current by changing size or orientation of circuit in stationary magnetic field OR

    changing magnetic field through stationary current

    Motion through magnetic field creates a potential difference

    This motion creates an electric field to balance the forces (see above)

    This in turn creates a motional emf (potential difference) of

    From this It can be seen a current may be induced in a circuit, using right

    hand rule and fact that current runs from positive to negative (like in figure

    to the right) then we can find direction and magnitude using

    In order for sliding wire to work and have constant velocity we must

    realise that pulling force is present and is equal to the magnetic force

    Also note that

    Eddy current are when a loop of non

    magnetic material is placed in between two

    magnets. This induces a current in the loop

  • and means a force must be applied to pull the loop out of the

    the magnetic field.

    Magnetic flux is the amount of magnetic field passing through a

    loop and is given by

    In a non-uniform magnetic field the flux is stated as

    Lens Law states:

    The induced emf created by this changing flux is given by Faradays Law (-ve because opposes

    the change of magnetic flux)

  • Changing magnetic field causes electric field in pinwheel shape.

    This is called a non-coloumb electric field as it rotates.

    This is created by magnetic field, where as coloumb electric field is

    created by positive and negative charges.

    We may calculate the electric field as

    |

    |

    From this we can get the equation for a solenoid

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    |

    |

    |

    Changing electric field also causes a magnetic field, but OPPOSITE IN

    DIRECTION TO LENS LAW (Maxwells)

    Maxwell found that these electromagnetic waves have speed

  • Discovery used practically in generators

    Transformers

    Like capacitors, inductors create a uniform magnetic field by use of a solenoid

    Instead of charge to voltage ratio, inductor uses flux to current

    We can then find the potential difference across this using faradays law such that

    |

    |

    Often used as a spark, closing a switch creates a large change in current.

    Electromagnetic Fields and Waves

    Overview of concepts

    Gauss Law: For any object enclosing a charge Qin, net electric flux is

    For a magnet, continuous lines therefore

    Faradays Law: An electric field and thus an emf can be created by a changing magnetic field

    Ampere Maxwell Law (note this is a correction to the previous Amperes Law): Current

    creates a magnetic field and magnetic flux is also a magnetic field so, B through a surface is

    (

    )

  • The lorentz force law describes how magnetic and electric fields effect a moving particle

    In Summary!

  • Constant current means increasing electric field but constant

    magnetic field induced.

    Magnetic field depends on rate of change of charge.

    For an electromagnetic wave, pointer is magnetic, thumb is

    electric, palm is velocity

    Electromagnetic intensity decreases linearly with time, e.g at

    20km the ampliturde is half what it was at 10km

    We find that:

    Should be noted that is in direction of

    at any point on the wave

    Electromagnetic waves have an intensity, which is the average energy transfer. Intensity is

    Note that light exerts momentum

    It follows that radiation pressure has an effect on an object, with pressure being

  • OPTICS Travelling Waves

    Wave source that oscillates with simple harmonic motion generates a sinusoidal wave

    Period of this wave is called, T

    Useful to define something called the wave number

    Displacement of a wave at time is equal to

    PHASE DIFFERENCE BETWEEN TWO POINTS OF A WAVE DEPENDS ONLY ON RATIO OF

    SEPERATION TO WAVELENGTH

    PHASE DIFFERENCE BETWEEN TWO WAVEFRONTS IS ALWAYS 2

  • Index of refraction of material is a ratio

    Wavelenght in material is

    E.g. in material there will be a smaller wavelength

    Doppler Effect

    Different wave lengths because moving source

    Wavelength of approaching source will be

  • NOTE THIS DIFFERS FOR THE PERSON MOVING TOWARDS SOURCE

    This is because waves move through medium, we get the equations

    For light waves if we calculate the wavelength from above we find that a receding

    source has a red shift while an approaching source has a blue shift.

    Superposition

    Superposition applies to waves as well

    Possible to have constructive and destructive interference

    When two or more waves are present at a point in space, the displacement is equal to

    the sum of the waves displacement

    Interference depends on the phase difference of waves,

    (

    )

    For sources with no phase shit max constructive and perfect destructive occur at

    and (

    ) respectively

    This is used in the real world for thin film coating on glasses (see example)

  • NOTE MOTION OF WAVES DOES NOT EFFECT POINTS OF INTERFERENCE

    Same equations apply for three dimensions as one dimension with r replacing x

    (

    )

    THESE TWO ONLY APPLY IF WAVES ARE IN PHASE OTHERWISE USE PREVIOUS TWO

  • Wave Optics

    Light is modelled in several different ways

    o Wave Model: Used under most

    circumstances and true for most

    o Ray Model: Light travels in a straight

    line, useful for modelling lenses

    o Photon Model: Deal with that later

    Youngs double slit experiment

    demonstrates lights wave like nature

    Slits are typically 0.1mm wide and 0.5mm

    apart

    Light waves interfere constructively to

    produce bright bands of light

    Can see that

    Follows that position of bright

    fringes

    Diffraction grating which is an opaque screen with n

    slits follows the same principles

    Often modelled as REFLECTION GRATING

    Single slit diffraction:

    Dominated by central maximum of

  • Ray Optics

    Objects are either self-luminous (sun, torch) or reflective (tree, people) The ray model states:

    o Light Rays travel in straight lines o Rays can cross o Travel forever unless contact with matter o Object is a source of light rays o Eye sees by diverging bundles of rays.

    Rays originate from every point on an object

    Object and image heights related by ratio

    Light reflects at the same angle it collided with material at

    Refraction occurs when material passes from one material to the other

    Not all light is refracted, some is reflected

    NOTE ANGLE IS MEASURED FROM LINE PERPENDICULAR TO SURFACE

    A point is reached where all light is reflected, Total Internal Reflection

    (

    )

    Vergence is the curvature of wavefront. Curvature of wavefront is

    The radius of the vergence is directly related to the vergence itself such that

    {

    }

  • Mirrors are used to direct light, given by equation

    Vergence for a mirror is

    NOTE VERGENCE POSITIVE FOR CONVERGING NEGATIVE FOR DIVERGING

    Lenses (spherical interfaces) are used to direct

    light, given by equation

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    Power can also be written as (noting that nin is the concave side and nout is the convex)

    Magnification is quite simply defined for mirrors and lens as

    Possible to define thin lens equation where there are two

    interfaces next to each other (see figure to the right)

    [

    ]

  • Eye can see to an angular size of

    If a single converging lens is used this

    angle can be even smaller such that

    using small angle approximation

    This leaves the magnification to be

    With a microscope this can be improved on even more so that we have a magnification

    The light gathering power of a microscope is also an important

    aspect, measured in numerical aperture, NA, it is defined as

  • Telescopes are another useful optical aperture with their magnification given by

    In magnification there is still diffraction (occurs passing through hole of any shape) as

    the ray model of light is not complete

    This means there is a central maximum, meaning there is a minimum spot size able to be

    projected

    In a real world situation it is difficult to produce a lens

    with a focal length less than its diameter so in reality

    Minimum angular resolution of a lens is called Rayleighs

    criterion

    X-ray diffraction occurs when rays of very short

    wavelengths pass through the crystalline structures of

    materials.

    X-rays strongly reflect when their angle of incidence is

  • RELATIVITY Reference Frames are the main concept to understand, once understood relativity

    should be easy, they can be said to

    o Extend infinitely in all directions

    o Experimenters are at rest in the frame

    o Velocity and distance is measured accurately from this frame

    Important to define an event as an activity that takes place at a definitive point at a

    definitive time in space. They are what REALLY happen.

    However measuring the event is the difficulty

    In each reference frame to measure events you must use metre sticks and clocks in

    that reference frame only

    Note the time t is the time the event ACTUALLY happened.

    SIMULTANEITY is when two events at different positions occur at the SAME time in a

    reference frame.

    Exploding firecracker on a moving cart experiment to explain simultaneity

    S commonly used to refer to rest frame of the moving object.

    Consider clock in moving frame. This clock measures the proper time such that measuring a

    time outside this reference frame yields the result

    Often said that the time interval between two ticks is the shortest in the reference frame

    where the clock is at rest.

  • Considering twin paradox, both twins think they will have the younger sibling.

    But this is not true as theory of relativity only holds in inertial reference frames and

    the second sibling goes there and back so person on earth would be older

    Length contraction also occurs given by relationship. Where is the proper length of

    object

    Can use the spacetime interval to compare events in all inertial reference frames as

    it is the same in all intervals

  • Galilean transforms are not valid in reference

    frames close to the speed of light

    Must use Lorentz Transformations, which all use the

    value

    The equations are then given as

    Should be noted that the x-values are only valid

    where and when the event actually occurs not where they are after a certain time.

    Should also be noted that the y and z values stay the same, e.g .

  • There is also variation between the traditional velocity

    transforms as seen to the right

    Where u is the frame of the moving object, v is the

    velocity between frames and u is from a separate rest

    frame.

    Again there is variation between traditional

    momentum and relativistic motion and we see that the

    law of conservation of momentum does not hold at

    large speeds. Momentum is actually given by

  • From this we can see that it is impossible for an object to go faster than the speed of

    light as more and more energy is required to accelerate and object and an infinite

    amount of energy is required to accelerate an object to the speed of light.

    It follows that an object has a rest energy and a kinetic energy of total

    In this equation it should be noted that E0

    ALWAYS has an energy regardless of the

    reference frame

    The subscript p implies we are referring to

    motion within a reference frame NOT motion

    of two reference frames relative to each other

    Note mass is not conserved, consider two colliding clay balls at same speed, if they collide

    and mould there will be no velocity and due to conservations of energy

    From this we learn that for conservation of energy to be true

    ( )

  • So mass and energy can be transferred but are NOT the same thing (think of fission).

    Skipped most of End of Classical Physics Chapter but a few useful things

    One electron volt is kinetic energy gained by an electron or proton if it accelerates

    through a potential difference of one volt

    Quantization

    Electromagnetic waves can be artificially created

    By shining light of a certain frequency at a substance you may

    emit electrons. Consider following experiment.

    Battery used to create potential difference and noted a few

    discoveries

    1. Current is directly proportional to the intensity of light

    2. When light is applied current occurs spontaneously

    3. Only emitted if a certain frequency, threshold frequency,

    is exceeded.

    4. Threshold frequency depends on metal that cathode is

    made of.

    5. Positive potential difference creates no change in current

    as increase. Negative potential difference does change

    current until at some point the change in voltage makes

    the current stop

    6. This value is the same for all light intensities.

    This shows that a minimum energy is required to free an electron from a metal such that

    We can consider the voltage required to stop an electron freed from the cathode as it

    approaches the anode to be

    However this classical interpretation does not account for a threshold frequency

    Einstein saw this and created his model that accounts for a threshold frequency

  • EINSTEINS EXPLANATION

    Atoms vibrate with a frequency of f

    Energy of an atom vibrating with frequency, f, has to have energy

    Einstein states that light arrives in light packets, called a Light Quantam, and each light

    quantam has energy

    Think of rain analogy, generally water flows like light, but with rain we get it in drops. The

    difference is intensity e.g intense energy is lots of rain or lots of light

    Einsteins three statements about light quanta

    1. All photons with energy travel at the speed of light

    2. Light quanta absorbed on all or nothing basis, e.g. substances can only emit or

    absorb 1,2 or 3 quanta, not 1.5

    3. Light quanta when absorbed by an electron gives ALL of its energy to ONE electron

    This lead us to the discovery that

    IF this where E0 is the energy required to remove an electron, then the

    electron leaves the metal becoming a photoelectron.

    This gives us the previously stated threshold frequency

    If the frequency is less than this threshold frequency, even for high intensity light no

    electrons will be ejected

    {

    }

    NOTE: Threshold frequency is directly proportional to

    the work function, metals with low work functions=low

    threshold and vice versa.

    This leads to us discovering that

    These light quanta later given the name photons

    No perfect analogy for a photon, some work well in

    some situations but not in others, however the

    energy created by photons arriving at a point is

    defined as power:

  • It was postulated by De Broglie that matter can have a wave like nature

    De Broglie then found that the wavelength of matter with momentum

    This means that matter undergoes interference like double slit experiment

    Considering a matter wave to be a travelling wave that is

    confined to a box

    This creates something called a standing wave that has

    a constant path

    Wavelength must be

    To satisfy this and the de Broglie wavelength formula

    This means that energy of a confined particle is quantised e.g. has certain energies

    Can rewrite this as

    Older models for atoms didnt explain stability or discrete spectra

    Bohrs model does and implies that

    1. Atom consists of negative electrons orbiting a positive nucleus (Rutherford)

    2. Atoms can only exist in certain stationary states

    3. Each of these states has a certain energy level En where E1< E2< E3< E4.

    4. Ground state E1 is stable and will always exist, other states may not, called excited

    states

    5. Atom can jump from one state to the other by absorbing or emitting a photon

    6. By absorbing photon it goes to a higher state

    7. By emitting it goes to a lower state

    8. Atom always seeks the lower state

  • Main additions to the Rutherford model are atoms can only exist at certain states

    and that atoms can jump from one state to another by absorbing just the right

    frequencies such that energy is conserved.

    This model implies that

    1. Matter is stable

    2. Atoms only emit certain spectra due to the set frequency and energy levels

    3. Spectra can be produced by collisions such as experiment at beginning of chapter

    4. This causes only certain wavelengths to be seen in spectra (suns show certain

    colours)

    5. This means each element has a certain spectra

    Particularly useful to observe a

    hydrogen atom

    After a long amount of calculations we

    find that there are set values for atom

    Note that the energies of the stationary states are negative as energy is required to

    keep the proton and electron near each other, e.g. it would take 13.60eV of energy

    to remove electron from ground state, hence E is called the ionisation energy

    It follows that electron must also have a certain momentum of

    We can find the wavelength emitted by a hydrogen atom when the state is altered

    It turns out these formulas work for all hydrogen-like ions in which there is one

    electron and there is an atomic number Z (He has Z=2, Li has Z=3)

  • Wave functions and Uncertainty

    Considering the double slit experiment there is no

    definite place where a photon will land.

    It is all probability with

    Combining this photon model with the wave model we

    can decipher that

    | |

    | |

    This equation is the statement that the probability of detecting a photon at a

    particular point is directly proportional to the light wave amplitude function

    Now we need to make an assumption that there is a continuous wave function for

    matter that is analogous for that of an electromagnetic amplitude function

    | |

    Only real difference here is that (x) is for particles and A(x) is for photons

    From this we can realise that the position of an atomic size particle is not well

    defined, however the function (x) defines it, it is like with x(t) in classical physics

    Should be noted the particle has a 100% chance of hitting somewhere.

    Can split up the place we are observing into many different slits to form an equation

    for the number of photons that will hit the area

    | |

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  • Previously we have described objects as either a particle

    or a wave but wave packets can account for the various

    properties of both

    Localisation is particle like

    Undergoes diffraction and interaction like wave

    Not entirely accurate but helpful for visualising problems

    Only approximately accurate because packets come in

    many different shapes and no precise definition of the

    time and frequency

  • It is interesting as you cannot define exactly when the wave packet arrives at a point

    (would you consider the front or centre)

    Because spread out over time you cannot say, therefore known formula is lower

    limit and it is actually better to say

    Matter has wave like characteristics so this equation must apply to matter also.

    Time interval is duration of wave packet as it passes a point

    Any sinusoidal wave must satisfy

    This leads us to the conclusion that the position and momentum of a particle cannot

    be known for certain with the statement

    This statement also applies for the y-axis

    As a basic this equation implies that if we measure a particles position x, with some

    uncertainty then the

    smaller this uncertainty

    is the larger the

    uncertainty for

    momentum HAS to be

  • Schrodingers equation is a method of calculating the wave function as discussed

    previously

    Considering particle with mass m, and mechanical energy E that can have its

    interactions with the surrounding environment characterised in one dimension by a

    potential energy function U(x) we have an equation

    [ ]

    JUST PRAY TO GOD THIS DOESN'T COME UP IN THE EXAM

  • Permittivity of free space - 0=8.854*10^-12 F m-1

    Permeability of free space - 0=4*10^-7 N A-2

    Coulomb Constant - k=1/(40)=8.998*109 N M2 C-2

    Electron charge - e=1.602*10-19 C

    Electron mass - me=9.109*10-31 kg

    Proton mass - mp=1.673*10-27 kg

    Unified atomic mass - u=1.661*10-27 kg

    Planck constant - h=6.626*10-34 J s

    Reduced planck constant - hbar=1.055*10-34 J s

    Avogadro Number - NA=6.022*1023 mol-1

    EQUATIONS

    ELECTRICS

    Coulombs Law

    Electric Field of a Pont Charge

    Electric Field of Dipole on Axis

    Electric Field of Dipole Perpendicular

    Surface Charge Density

    Linear Charge Density

    Electric Field of Point Charge

    Electric Field of Infinite Line

    | |

    Electric Field of Infinite Plane

    Electric Field of Sphere

    Parallel Plate Capacitor Electric Field

    Note outside the plates E=0

    Force on a moving charged particle

  • Acceleration on particle (assuming electric field is only force)

    Circular Motion in a non-uniform electric field | |

    Dipole Torque in Uniform Field

    (torque greatest when p is perpendicular to E)

    Electric Flux

    Gausss Law

    Charge on a conductor in equillibrium

    Electrical Energy

    Energy of a system (not particle)

    Note: +ve for like charges, -ve for opposite

    Potential energy of a Dipole

    Theta is angle between dipole and field

    Electric Potential Energy (V=Electric Potential)

    Potential inside a parallel plate capacitor

    Electric Potential of a point charge

    Electric Potential of a Charged Sphere

    Sum of Electric Potential

    Potential Energy

    Battery Potential Energy

    Electric Potential from Field

    Charge on Capacitor

    Capacitor in Series (

    )

    Capacitor in Parallel

    Electron current

    Current Density

    Field Strength in Wire

    Resistivity & Conductivity

    Resistance

  • Power of Battery

    Energy of battery

    MAGNETISM

    Biot Savart Law (

    )

    Small segment of wire

    Magnetic field at centre of coil

    Magnetic field Dipole

    Magnetic Dipole Moment created by current loop

    Amperes Law

    Magnetic field through solenoid

    Magnetic field force on moving particle

    Cyclotron Motion

    Force on current carrying wires

    Force on parallel wires

    Torque

    Motional emf

    Induced current in a wire

    Magnetic flux

    Faradays Law (induced emf by changing flux)

    Faradays Law alternative (for induced electric field)

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    Emf in generator

    Inductance

    Potential difference across an inductor

    Ampere-Maxwell Law (

    )

    Lorentz force Law

    Velocity of Electromagnetic Wave

    Intensity of electromagnetic Wave

  • Radiation pressure from EM waves

    IMPORTANT EQUATIONS

    OPTICS

    Velocity of wave

    Wavelength of wave

    Displacement of a wave at time zero in one dimension

    Wave number

    Displacement of wave at any time

    Index of refraction

    Wavelength in material

    Doppler Effect for source approaching person

    Doppler Effect for source receding from person

    Doppler effect for person approaching source ( )

    Doppler effect for person receding from source ( )

    Maximum constructive interference

    Perfect destructive interference

    (

    )

  • Youngs Double Slit Experiment

    Diffraction Grating

    Single Slit Diffraction

    Distance and Height relationship

    Snells Law of Refraction

    Total Internal Reflection (

    )

    Vergences {

    }

    Focal Point

    Mirror Equation

    Mirror Vergence

    Lens Vergence

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    Power for Lens

    In is concave, out is convex

  • Magnification for lens and mirrors

    Thin Lens Equation

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    ]

    Power in air

    Angular size of unaided eye

    Angular size of object with lens

    Angular Magnification

    Microscope magnification

    Light gathering power

    Telescope Magnification

    Central maximum

    Minimum central maximum

    Rayleighs Criterion (minimum resolution of a lens)

    X-ray reflection

    RELATIVITY

    Time Dilation

    Length Contraction

    Spacetime Interval

    Lorentz Transforms

    Lorentz velocity Transforms

  • Relativistic motion

    Relativistic energy

    MODERN PHYSICS

    Classical Photoelectric effect

    Energy of a photon

    Einstein Stopping Potential

    Photon Power

    De Broglie Wavelength

    Energy of confined particle

    Hydrogen Atom radii

    Hydrogen Atom electron velocity

    Hydrogen Atom Ionisation Energy

    Hydrogen Electron Angular Momentum

    Wavelength emitted in hydrogen atom

    Hydrogen Like Ions (only one electron)

    Photon experiment expected photons in an area

    Photon experiment expected photons in an area w.r.t light intensity

    | |

  • Wave Function for matter | |

    Amount of matter in an area | |

    Wave packet Lower Limit

    Wave packet actuality

    Heisenberg Principle

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    Schrodingers Equation

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