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In the case of some electrical appliances, the chemical reactions that take place in the cells on which they are powered result in a potential difference between their terminals, which causes the electrons to be propelled in their respective directions. Energy must be expanded by the source in order to maintain the current flow. Some of the energy is put to use in beneficial activities, such as moving the fan blades in the case of electrically powered fans, or in other ways. When there is any remaining energy, it is used or increased by generating heat, which raises the temperature of the device. It is possible to use a totally resistive circuit in an appliance, but a significant amount of energy is wasted entirely in the form of what we refer to as heat. The heating impact of electric current is what this is referred to as.
Heating effect of the electric current diagram
When electricity runs through a conductor, heat energy is generated within the conductor. When it comes to the heating effects of electric current, there are three elements to consider:
The conductor’s resistance is measured. A higher resistance results in the production of more heat.
The length of time that the current is in motion. The amount of heat produced increases exponentially with the length of time.
The amount of heat generated increases according to the amount of current.
Since an electric current (I) flows through a resistive conductor (R) over a time interval (t), the heating effect produced by I through R is given by H = I2Rt. The Joule’s equation for electrical heating is represented by this equation.
How to reduce the heating effect of electric current
Derivation of Formula
Consider the case where current (I) is flowing through a conductor AB with resistance R for a period of time t. The heat created in the conductor may be calculated by considering as well that the potential difference applied across its two ends is denoted by the letter V.
Now, the total amount of work required to move a charge q from point A to point B can be calculated as follows:
W = q X V …………..(1)
charge = current × time
q = I X t
and V = I X R (by Ohm’s law)
Putting the values of q and V in equation (1), we get
W = (I X t) X (I X R)
Or W = I2Rt
We may now replace the symbol for work done with the symbol for heat created, assuming that 100% of the work done is turned into heat energy. So,
H = I2RT
Applications of heating effect of current
Filament lamps are made up of a tungsten wire that is enclosed in a glass bulb that has been vacuumed to eliminate the air. The reason for this is that air would oxidize the filament. The filament is heated to a high temperature and becomes white-hot during the heating process. Tungsten is employed because of its high melting point (34000 degrees Celsius). Low-pressure inert gases, such as argon or nitrogen, are used to fill the bulb, which decreases the evaporation of the tungsten wire in the filament. One downside of the inert gas, on the other hand, is that it creates convection currents that cool the filament, which is undesirable. Convection heat loss is reduced by coiling the wire, which minimizes the amount of space it takes up and so reduces the amount of heat lost through convection.
Fluorescent lamps- These lamps are more efficient than filament lamps and last a lot longer, too. Mercury vapour fills the glass tube, and when it’s turned on, it emits ultraviolet light. There is a lot of radiation in this tube, and the powder in it glows (fluoresces), which means it shows up in the dark. Different types of powders make different colours. Keep in mind that fluorescent lamps are expensive to put in, but their running costs are a lot less.
Electric Heater- In an electrical heater, a coil made of nichrome wire with a very high resistance is most regularly and extensively utilized. The coil is rotated or twisted on grooves made of ceramic material such as iron plate or china clay plate, which are used to rotate or wind the coil. When electricity travels through the coil, it immediately gets warm or heated, and this heat is then extensively used to warm the cooking utensils in which we prepare food. The usage of electrical room heaters in mountainous places allows people to keep their rooms warm and heated while avoiding exposure to the freezing temperatures outside.
Electric Iron- Mica is placed between the metal part and the electrical coil in an iron, which is an insulator by nature. 2. Electric Iron: An electric iron is a device that uses electricity to conduct electricity. Due to the constant passage of current, the iron’s coil becomes warm or heated. This heat is then passed on or transferred to the metallic component by means of the mica that was used. In the end, after a period of time, the metallic component becomes extremely hot, or whatever temperature we have set it to and is then utilized for ironing different types of clothing according to our preferences.
Conclusion
A wire becomes hot when an electric current is sent through it, and this heat is converted into energy, which is referred to as the heating effect of the current. This energy is defined as the quantity of energy that is dissipated in the form of heat by the resistor during operation. Whenever electricity passes through a conductor, heat energy is produced within the conductor. There are three factors that influence the heating impact of an electric current; they are as follows:
The conductor’s resistance is denoted by the letter R. A higher resistance results in the production of more heat. The length of time, t, during which current flows. The amount of heat produced increases according to the length of time. The amount of current, I. The greater the amount of current, the greater the amount of heat generated. Since an electric current (I) flows through a resistive conductor (R) over a time interval (t), the heating effect produced by I through R is given by H = I2Rt. Joule’s equation of electrical heating is the name given to this equation.
