Physics II
we can said that matter can be regarded as composed of three kinds of elementary particles; proton, neutron (no charge), and electron. Particle Symbol Charge (e) Mass (kg) Proton P +1 1.67 10-27 Neutron N 0 1.67 10-27 Electron e - -1 9.11 10-31
It states that the force between two charged particles varies directly as the product of their charges and inversely as the square of the separation distance. Electric field Electric field defines as "the area (region) around an electric charge where its electric effects appear"
The strength of the electric field at a point is equal to the force experienced by a unit positive test charge placed at that point. Electric flux The electric flux is the number of electric lines of force crossing a supposed surface in the field and perpendicular to it.
The number of electric lines of force crossing a closed surface and perpendicular to it; equal to the sum of charges present inside this surface divided by the permittivity constant of the medium inside the surface.
the electric field can be described by the electric potential; which is a scalar quantity. The relation between the potential and electric field
Calculation of E from V If we take in consideration the components of E in the three axis (X,Y,Z) then,
A capacitor is a device that stores charge. Often, although certainly not always, it consists of two conductors separated by an insulator or dielectric; the two conductors charged with two equal opposite charges.
The potential of spherical conductor of radius R and charge q is given by The capacitance of spherical conductor
To find the energy stored in a charged capacitor, we must calculate the work done to charge the capacitor The energy density Energy density is the stored energy per unit volume.
The two most common combinations are combination of capacitors in series and in parallel.
we insert an insulator or dielectric to fill the space between the capacitor plates
The conduction electrons in an isolated metallic conductor are in random motion. If we connect the ends of conductor to a battery, an electric field created at the surface of conductor and will act on the conduction electrons and they acquire a constant average drift speed in the opposite direction of the electric field direction.
The electric current The current density The relation between the current density and the drift speed of electrons
The electric resistance Resistivity of material Conductivity of material
The resistance of a cylindrical conductor The variation of resistivity with temperature Ohm's law
The electromotive force It is the work done by the device per unit charge in moving the charge from its low potential terminal to its high potential terminal.
Electric energy and power in electric circuit The power supplied by the battery is the work done per unit time
Resistors in series and in parallel Series combination Parallel combination
Kirchhoff's rules 1. Junction Rule The sum of the currents entering any junction must equal the sum of the currents leaving that junction. I 1 = I 2 + I 3
2. Loop Rule The sum of the potential differences across all the elements around any closed circuit loop must be zero
q C R C circuits 1. Charging a capacitor a R V b i + + - - C
2. Discharging a capacitor
Magnetism is a force that acts at a distance and is caused by a magnetic field. Many historians of science believe that the compass, which uses a magnetic needle, was used in China as early as the 13th century B.C., its invention being of Arabic or Indian origin. The early Greeks knew about magnetism as early as 800 B.C.
The Magnetic Field It is found at the space around a magnet or a current carrying conductor. The basic vector represents the magnetic field B is called the magnetic induction or the magnetic flux density
Magnetic flux It is defined as the total number of magnetic field lines crossing normally through the area. The Magnetic force acting on a charged particle If a particle of mass m carries a charge q is moving with velocity v in a magnetic field, it will experience a deflecting magnetic force.
Magnetic Force Acting on a Current-Carrying Conductor When a current-carrying wire is placed in a magnetic field, each electron, contribution to the current, experiences a magnetic force Torque on a Current Loop in a Uniform Magnetic Field
Magnetic dipole the torque on current carry loop in a magnetic field is The Magnetic Potential Energy of Magnetic Dipole in a Field The potential energy of a magnetic dipole in a magnetic field depends on the orientation of the dipole in the magnetic field and is given by
Motion of a Charged Particle in a Uniform Magnetic Field Magnetic forces can cause charged particles to move in circular or spiral paths The cyclotron radius The angular speed of the particle The cyclotron frequency The period of motion
This chapter deals with the basic relationship suggests that the currents generate magnetic fields and magnetic fields exert forces on the current.
Calculating of magnetic field The calculation of the magnetic field can be carried by : 1. Biot-Savart law: This law can be used for different current distribution.
2. Ampere's Law Ampere s law stated that the line integral of around any closed path equals, where is the total continuous current passing through any surface bounded by the closed path.
Faraday s Law of Induction The electromotive force can be induced in a circuit by a changing magnetic field. Faraday's law of induction was deduced to explain this phenomenon.
Motional Electromotive Force Lenz s Law This law states that the polarity of the induced is such that it tends to produce a current that creates a magnetic flux to oppose the change in magnetic flux that producing it.
Inductance If two coils are near each other, a current in one coil will set up a flux through the second coil. The changing of the current will cause a change in this flux and an induced will appear in the second coil according to Faraday's law. Self Induction
RL circuit Energy Stored in the Magnetic Field of an Inductor Magnetic Energy Density
The Mutual Induction
Magnetic moment of dipoles Gauss s Law in Magnetism Magnetic field strength
Ferromagnetism Paramagnetism
Maxwell s Equations
Plane Electromagnetic Waves Energy Carried by Electromagnetic Waves The rate of flow of energy in an electromagnetic wave is described by a vector
Wave intensity Momentum and Radiation Pressure
The Spectrum of Electromagnetic waves
Conditions for interference The sources must be coherent The sources must be monochromatic The superposition principle must apply. Types of interference Interference in light waves from two sources (Young's Double-Slit). Interference in thin films. Interference due to Plano-Convex lens (Newton's Rings).
Polarization of light waves Methods of production of polarization Polarization by selective absorption Polarization by reflection Polarization by double refraction Polarization by scattering
Optical activity A substance is said to be optically active if it rotates the plane of polarization of transmitted light. The angle through which the light is rotated by a specific material depends on the length of the sample and on the concentration if the substance is in solution
Diffraction of waves Methods of diffraction Diffraction by single slit The diffraction Grating