Electromotive force – emf, Physics

Assignment Help:

ELECTROMOTIVE FORCE – EMF:

To make use of electricity by provision of an electric current, the potential different must be maintained. That is, the positive and negative charge must be continuously replenished. A cell (or battery) uses chemical energy to maintain the potential difference.

Another device used for this purpose is the generator, which uses electro-mechanical energy to maintain the potential difference. The potential difference across the terminals of the source (cell, battery or generator) when it is not supplying current, is called Electromotive Force (emf), since this is a measure of the force available to push electrons around the circuit. In a circuit with a current flowing, the potential difference across the terminals of the source is always less than the emf and is referred to as the terminal voltage.


Related Discussions:- Electromotive force – emf

Explain the molecular theory of surface tension, (i)  On the average, parti...

(i)  On the average, particles are separated by a distance of the order of 10-10 m and exert a force of attraction of the order of 10-11 N on each other. (ii)  The force of atta

Comparison among types of harmonic motion, Can you give the graphical compa...

Can you give the graphical comparison among the following three kinds of harmonic motion: i. Under damped harmonic motion ii. Over damped harmonic motion iii. Critically

Explain bi-prism experiment, Explain why a narrow slit is used in case of B...

Explain why a narrow slit is used in case of Bi-prism experiment where as an extended source is used in Newton's rings experiment?

Mechanical stressing, Mechanical stressing: When a material undergoes a me...

Mechanical stressing: When a material undergoes a mechanical treatment, its resistivity changes due to mechanical distortion of the crystal structures. The localized strain produc

Motor, illustrate the parts and function of motor

illustrate the parts and function of motor

Explain torque, A 92-kg man uses a 3.05-m board to attempt to move a boulde...

A 92-kg man uses a 3.05-m board to attempt to move a boulder, as shown in the diagram below. He pulls the end of the board with a force equal to his weight and is able to move it t

Demonstrate resonance and forced vibrations, Demonstrate resonance and forc...

Demonstrate resonance and forced vibrations Consider four simple pendulums P,Q,R and S suspended from horizontal stretched rubber card AB. Let the lengths of pendulums p and R

Arago spot, Arago spot (D.F.J. Arago) A bright spot which appears in th...

Arago spot (D.F.J. Arago) A bright spot which appears in the shadow of a uniform disc being backlit through monochromatic light emanating from a point source.

What is rarer and denser medium , A medium is known as denser if the veloci...

A medium is known as denser if the velocity of ray in that phase is fewer than the speed of the wave in other phase.     In comparison to air velocity of sound is main in water,

Electric field, How we can calculate the magnitude of electric field above ...

How we can calculate the magnitude of electric field above a sheet charged with voltage V where we know the bulk conductivity and relative permittivity of the space above the sheet

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd