Skip to main content

12th physics online class and notes -Electromagnetic Waves

12th physics online class and notes -Electromagnetic Waves

Physics notes for class 12 : How are Electromagnetic waves produced?
Electromagnetic waves are produced by an accelerated or de-accelerated charge or LC circuit.
Transverse Nature of Electromagnetic waves:The Electromagnetic waves are transverse in nature with the electric and magnetic fields perpendicular to the direction of propagation.

Electromagnetic waves: The waves propagating in space through electric and magnetic fields varying in space and time simultaneously are called electromagnetic waves.
  • An electromagnetic wave consists of a fluctuating electric field and a fluctuating magnetic field of the same frequency and the same phase.
  • The electric and magnetic fields are mutually perpendicular and also perpendicular to the direction of propagation of the wave.
  • In the propagation of an electromagnetic wave, a varying electric field E gives rise to a varying magnetic field and so on. In this way, electric and magnetic fields of the wave sustain each other.

Characteristics of electromagnetic waves:
  • The electromagnetic waves travel in free space with speed of light irrespective of their wave length.
  • Electromagnetic waves are transverse in nature.
  • Electromagnetic waves do not need a material medium for their
propagation.
  • Electromagnetic waves are produced by accelerated charges.
  • Electromagnetic waves obey the principle of superposition.

  • Electromagnetic waves are neutral so they are not deflected by electric and magnetic fields.
  • The ratio of magnitudes of electric and magnetic field vectors in free space is constant and equal to c
ie c = E/B = 3×108m/s

  • Electromagnetic waves show properties of reflection, refraction, interference,
diffraction and polarisation.
For more NCERT physics class 12 articles, video lectures, NCERT Solutions for class 12, sample papers, CBSE Guide, updates on CBSE board exams, enroll with Takshila Learning

Comments

Popular posts from this blog

Allotment of DIN (Director Identification Number)

Allotment of DIN (Director Identification Number) CS professional course :  Section 153 of the Companies Act, 2013 read with Rule 9 of the Companies (Appointment and Qualification of Directors) Rules, 2014 Every individual intending to be appointed as a director as a director of a company shall make an application for allotment of Director Identification Number (DIN) to the Central Government in such form and manner and along with such fees as may be prescribed. Rule 9 of Companies (Appointment and Qualification of Directors) Rules, 2014 (1) Every Individual, who is to be appointed as a director of a company shall make an application electronically in Form DIR 3, to the Central Government for the allotment of a DIN along with such fees as provided in the Companies (Registration Offices and Fees) Rules, 2014. (2) The Central Government shall provide an electronic system to facilitate submission of an application for the allotment of DIN through the portal on the MCA21...

PURCHASED GOODWILL METHOD UNDER IND AS 103

The acquisition of subsidiaries results in  Goodwill calculation  and also records net assets of the subsidiary at fair value on the date of acquisition. Let’s get answers to all the questions related to Goodwill, valuation of NCI, and impairment relating to them. Q1 – What are the ways in which an entity can make payment for purchase consideration? ANS: – Cash – Share exchange – Deferred payment – Contingent consideration Q2 – How is deferred payment dealt, when it forms part of purchase consideration? ANS:  The deferred payment is discounted to present value and included in the cost of consideration. At the end of each year, the liability is increased by unwinding the discount, until the payment is settled. For example, An amount of Rs. 108,000 was deferred to be paid after 2 years. The discount rate applicable is 8%. The net present value today of Rs. 108,000 is equal to (108,000 * 1) / (1.08) ^2)= Rs. 92,593 included in purchase consideration. A liability of Rs. 92,59...

Importance of Rivers - General Awareness

Importance of Rivers Rivers carry nutrients and areas around the earth. It plays an important role in the water cycle of rivers and acts as a drainage channel for surface water. This leaves about 75% of the Earth’s surface. Rivers provide food and habitat for many living things on earth. In addition, rare trees and plants grow along the rivers. Otters, ducks, and beavers build houses along the river. Plants such as Buller and reeds grow along the river. Some animals use the river for food and drink. Birds like Kingfishers eat small fish from the river.  Animals such as deer, lions, and elephants drink water from rivers. Animals like bears fish from rivers. The Deltas River is home to a wide variety of wildlife. Mammals, birds, and insects use the delta for their homes and food. Provides rivers, routes, and travel routes for trade, exploration, and recreation. The valleys and plains near the rivers provide fertile soil. Farmers in arid areas irrigate their crops with water from near...