1. Heating effect of current
-In previous chapter while discussing electric energy and power ,we learned that IΔV amount of energy is lost per second when a current I flows through a potential ΔV and this energy appears in the form of heat energy
-Due to the conversion of electric energy into heat energy the conductor becomes hot .This effect is known as Joule's Heating and this heating is thermodynamics irreversible.
Cause Behind Joule's Heating:-
-Explanation behind the Joule's heating is that when a potential difference ΔV is maintained between the ends of a conductor,the free electrons in the conductor are accelerated towards the higher potential end of the conductor
-In their way electrons frequently collided withe the positive ions of the conductor due to which their velocity decreased
-This the energy electrons gained on account of acceleration is transferred to the positive lattice ions or atoms and electrons then returns to their equilibrium distribution of velocities
Thus ,lattice ions receives energy randomly at the average rate of IΔV per unit time
-Ions spends this energy by vibrating about their mean positions resulting in rise in the temperature of the conductor
-This way Joule's heating nothing but the conversion of electrical energy into heat energy
-We know that currents flows in a conductor whenever there is a electric potential difference betweens the ends of the conductor If there is a temperature difference between the ends of the conductor then thermal energy flows from hotter end to the colder ends
-Thermal energy flows may also be carries by the electrons in the conductor and hence resulting the presence of electric current
-At the hotter end of the conductor electrons have slightly higher kinetic energy and hence they move faster
-So there is net flow of current towards the end of the conductor with lower temperature.Thus an electric current exists in the conductor due to the difference in the temperature of two ends of the conductor
-This phenonmenon due to which electricity is produced when two ends of the conductor are kept at different temperature is known as thermoelectricty
For more visit Heating effects of current
Class 9 physics notes on chapter motion is now available at the following link CLASS 9 MOTION NOTES (FULL LENGTH)
Question1: A charge Q is divided in two parts q and Q - q separated by a distance R. If force between the two charges is maximum, find the ...
Coherent sources are those sources of light which emit continous light waves of same wavelength , same frequency and are in same phase or h...
Our New Free physics ebooks (pdfs) are available at this link . Hope you lile them.
Unit I: Physical World and Measurement (Periods 10) Physics: Scope and excitement; nature of physical laws; Physics, technology and society...
ADVANTAGES The generation of A.C. is cheaper than that of D.C. A.C. machines are simple , robust and do mot require much attention for the...
Hi all here in this article i am giving some tips and tricks to solve problems in mechanics. To master problem solving skill you need to pra...
1.A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x i...
Many times i have had users ask me a question which book to opt between H.C Verma Concepts of physics and NCERT physics books . My answer ...
Unit I: Electrostatics (Periods 25) Electric charges and their conservation. Coulomb’s law – force between two point charges, forces betwee...