Chapter-10|Wave Optics|NCERT 12th Physics: Proof for laws of Reflection at a Plane Surface (By Huygens’ Wave theory): When parallel rays comes from infinity at any instant a ray touches point A and at that time another ray touches point B, At that time first wavefront AB will be formed and it will be perpendicular to […]
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Chapter-10|Wave Optics|NCERT 12th Physics: Huygens’ Principle: Huygens’ principle gives the shape of the wavefront at any time and allows us to determine the shape of the wavefront at a latter time. According to Huygens’ Principle (I) Every point on a wavefront acts as source of secondary disturbances which emits their own wavelets called secondary wavelets.
Chapter-10|Wave Optics|NCERT 12th Physics: According to huygens light is a mechanical wave (require a medium). Huygens supposed the existence of a hypothetical medium called “luminiferous Ether” which filled the entire space through which Sun rays comes on Earth. This medium was supposed to be massless with extremely high elasticity and very low density. Wavefront: A
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Uses of Electromagnetic Waves: Uses of electromagnetic waves are as follows 1.Radio Wave:- (I) These waves are used in in amplitude modulation(AM). (II) These are used in frequency modulation(FM) (III) These are used in cell phones (IV) These are used in television broadcasting(TV) 2.Microwave:- (I) These are used in cooking purpose
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Electromagnetic Spectrum: The the orderly arrangement of electromagnetic wave in increasing or decreasing order of wavelength (λ) or frequency(υ) is called electromagnetic spectrum. It consist of following waves. 1. Radio waves 2. Microwaves 3. Infrared waves. 4. Visible or light rays. 5. Ultraviolet rays. 6. X-rays 7. Gamma(γ) rays.
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Characteristics of Electromagnetic Waves: 1. Electromagnetic waves are produced by accelerated charge. 2. These waves do not required any material medium for propagation. 3. It travel with the speed of light. 4. Electromagnetic waves are transverse in nature. 5. The energy in electromagnetic waves is divided on an average, equally between
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Electromagnetic Waves: Electromagnetic waves are the waves which are produced due to change in electric field E and magnetic field B Sinusoidally and propagating through space such that the two fields are perpendicular to each other and perpendicular to the direction of wave propagation. Source of Electromagnetic Waves: An oscillating charge
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Maxwell’s Equations: Maxwell’s equations are the basic laws of electric city and Magnetism. All the basic principles of electromagnetism can be explained in terms of four fundamental equations call maxwell’s equations. Maxwell did not discovered four equations, but he worked on them and stated that these four fundamental equations define complete
Chapter-8|Electromagnetic Waves|NCERT 12th Physics: Displacement Current: Ampere’s circuital law state that the line integral of magnetic field B, around any closed path is equal to μ₀ times the total current threading the closed path i.e According to Maxwell the above equation is logically inconsistent. With the help of following observation he prove it. Maxwell’s Experiment to Prove
Chapter-7|Alternating Current |NCERT 12th Physics: Wattless Current: The current which consumes no power for its maintenance in the circuit is called wattless current of idle current. Or The current in AC circuit is said to be wattless if the average power consumed in the circuit is zero. The average power of a given circuit is
