Electric Current and its Heating Effect
The heating effect of the electric current means when an electric current flows through a conductor, then it becomes heated, do you know what is the mechanism that heater glows reddish, irons becomes heated when you connect those to an electric circuit.
In this post, you will get all the answers to the questions which confuse almost all students.
What is resistance, charge, electric current, the heating effect of current?
Why is the direction of electric current is opposite to the flow of electrons?
When a current flows through a conductor, heat is dissipated through it. This heat energy is nothing but a work done by a flowing charge to overcome the resistance of the conductor.
Resistance. It is a characteristic of a substance opposing the flow of electric current.
It is one of the properties of the substance when the exchange of electron takes place either atom loses electrons or gains electrons if it lose electrons then atom transforms into cation and if it gains electrons it forms an anion. In the liquid, the cation drifts towards the negative electrode and the anion drift towards the positive electrode maintaining the flow of electric current.
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In solids or say metals, the current flow due to the flow of electrons, in metallic atoms, the valance electrons loosen because of the weak force of attraction exerted by the positive charge at the nucleus. These free electrons move freely within the conductor, when a battery is connected in the circuit a potential difference is developed across both of the ends of the conductor that compel the electrons to move from one end to another end generating the current. The emission of charge takes place in a quantized way. The charge emitted in the form of ne, where e= charge in an electron.
q = ne
Therefore the number of electrons in 1C charge
What is current? The current is the rate of flow of charge.
Why is current shown in the direction from positive to negative?
The way in which current flows in the circuit is, the negative terminal emits ne negative charge and at the same time positive terminal emits positive charge of the amount ne, it is the way how current flows in the circuit. The direction of the current is shown in the direction of a positive charge. Ever since Benjamin Franklin discovered electricity the direction of current conventionally is shown from positive to negative or it may be assumed that as all the type of current flows from high magnitude to lower magnitude as the wind blows from high pressure to lower pressure, water flows from a higher altitude to lower altitude, matter flows from high concentration to lower concentration,on the same way direction of current is logically is shown from positive to negative.
The SI unit of charge is the coulomb, so the unit of current = C/s= ampere
What is electrical energy?
Electric energy is the heat energy dissipated due to the resistance in the circuit.
The relation between work done, voltage and charge is given by the following formula.
V = W/Q
Here W is the work done on charge Q carrying it from one end of the conductor to another end against the resistance of the conductor, this work done is dissipated in the form of heat. this heat increases as per the time the current accessible in the circuit.
As we know V =iR, Q= it
Work = Energy transferred = Heat dissipated
W = H
V = W/Q ⇒ W = VQ
P= W/t = VQ/t = Vit/t = iV…….(i)
Power = Volage × Electric current
From Ohm’s law, we have, V = iR, substituting in eq.(i)
P = i× iR = i² R, Power = current²× Resistance
Since Work = Power/time ⇒Enegy = Power/time (Work↔Energy) ⇒H = P/t
Here energy means the heat dissipated through a current-carrying conductor
H = Pt = Vit from (i)
H = iR.it, From (4)
H = i²Rt
Henceforth the heating effect created by an electric current, through a conductor of resistance, R for a time period t is given by H = i²Rt. This relation is called Joule’s equation of electrical heating.
Application of heating effect is used in day to day life as an example of electric iron and heater, mostly an alloy nichrome is used made of nickel, chromium, and iron although third component iron could be substituted by other metals.
Nichrome is used in heating effect because it has high resistance, after even an excess of heating it is never oxidized, so it is long-lasting.
This is the study stuff useful for high school students, please write your comment and subscribe to this website if you liked it.