Home » Electricity & Megnetism (page 2)

Electricity & Megnetism

Faraday’s law of electromagnetic induction

Faraday’s Experiments: Faraday’s law of induction was discovered through experiments carried out by Micheal Faraday in England In 1831 and by Joseph Henry in the United States at about the same time. *Even through Faraday published his results first, which gives him priority of discovery, the SI unit of inductance is called the henry (abbreviation H). On the other hand, ...

Read More »

Lenz’s Law of electromagnetic induction

What is Lenz’s Law? “The direction of induced current is always so as to oppose the change which causes the current.” A mathematical expression of Faraday’s law of electromagnetic induction was derived as: ε = – N ΔΦ/Δt The minus sign in the expression is very important.It has to do with the direction of the induced emf.To determine the direction we ...

Read More »

Electromagnetic radiation spectrum

What is Electromagnetic Spectrum: The word spectrum comes from a Latin word meaning “form” or “appearance”. Other familiar words from the same root include “spectacle” and “species.” Newton introduced word to describe the rainbow-like image that resulted when a beam of sunlight passed through a glass prism. Today we speak of the electromagnetic spectrum to indicate the many different kinds ...

Read More »

Wheatstone bridge strain gauge

The Wheatstone Bridge: The Wheatstone bridge circuit is widely used to precisely measure resistance. Also, the bridge is used in conjunction with transducers to measure physical quantities such as strain,temperature , and pressure. Transducers are devices that sense a change in a physical parameter and convert that change into an electrical quantity such as a change in resistance. For example, a ...

Read More »

Difference between Inductor and capacitor

What is Inductor? When a length of wire is formed into a coil,it becomes a basic inductor. The term coil and inductor are used interchangeably.Current through the coil produced an electromagnetic field, as illustrated. The magnetic lines of force around each loop (turn) in the winding of the coil effectively add to the lines of force around the adjoining loops, ...

Read More »

Electromagnetic induction applications

Electromagnetic Induction: As soon as Oersted discovered that electric currents produce magnetic fields,many scientist began to look for the reverse effect, that is, to cause an electric current by means of a magnetic field. In 1831 Michael Faraday in England and at the same time Joseph Henry in USA observed that an emf is set up in a conductor when ...

Read More »

What is modulation and demodulation

What is modulation? Until the process of superimposing a low frequency (long wave) voice information component on a high frequency (short wave) carrier signal was perfected,the most widely used form of communication was a system based on the transmission of a continuous wave (CW) signal.With this system,the signal was interrupted periodically (Morse code) to produce a coded message.The CW system ...

Read More »

How does electric motor works

What is Electric Motor? An electric motor is an electromechanical device that converts electrical energy into mechanical energy.Electrical motors can be run as generators and vice versa, although this is not always practical. The Motor Principle: When a current-carrying conductor is located in an external magnetic field perpendicular to the conductor, the conductor experiences a force perpendicular to itself and ...

Read More »

magnets how do they work

What are Magnets? A permanent magnet has a magnetic field surrounding it. A magnet field can be envisioned to consist of lines of force that radiate from the north pole (N) to the south pole (S) and back to the north pole through the magnetic material. A permanent magnet, such as the bar magnet has a magnetic field surrounding it that ...

Read More »

What is Transducer

What are transducers? “A transducer is an electronic device that converts energy from one form to another.”Common examples include microphones,loudspeakers,thermometers,position and pressure sensors and antenna.Although not generally thought of as transducers,photocells,LEDs,and even common light bulbs are transducers. Efficiency of transducer: Efficiency is an important consideration in any transducer.Transducer efficiency is defined as:”The ratio of the power output in the desired ...

Read More »