Last updated on April 13th, 2023 at 03:53 pm
In this post, we will discuss some applications of the heating effect of current (applications of Joule heating).
Also, read this post on Joule Heating numerical: heating effect of electric current class 10 numericals
Applications of the heating effect of current | Joule Heating Applications
Here are some examples of applications of Joule heating (Applications of the heating effect of current).
(i) Electric heating device
Electric iron, electric heater, and electric toaster are some of the appliances that work on the principle of heating effect of current. In these appliances, Nichrome which is an alloy of nickel and chromium is used as the heating element for the following reasons.
(1) It has a high specific resistance
(2) It has a high melting point
(3) It is not easily oxidized
(ii) Fuse wire
Fuse wire is an alloy of lead 37% and tin 63%. It is connected in series in an electric circuit. It has high resistance and a low melting point. When a large current flows through a circuit due to short-circuiting, the fuse wire melts due to heating and hence the circuit becomes open. Therefore, electric appliances are saved from damage.
(iii) Electric bulb
Since the resistance of the filament in the bulb is high, the quantity of heat produced is also high. Therefore, the filament is heated to incandescence and emits light. Tungsten with a high melting point (3380 oC) is used as the filament. The filament is usually enclosed in a glass bulb containing some inert gas at low pressure.
Electric arc and electric welding also work on the principle of the heating effect of current.
In some cases such as transformers and dynamos, the Joule heating effect is undesirable. These devices are designed in such a way as to reduce the loss of energy due to heating.