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प्रश्न
Explain the heating effect of electric current.
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उत्तर
- When an electric current passes through a wire, the electrical energy is converted to heat.
- In heating appliances, the heating element is made up of materials with high melting point. An example of such a material is nichrome (an alloy of nickel, iron and chromium).
- The heating effect of electric current has many practical applications.
- The electric bulb, geyser, iron box, immersible water heater are based on this effect.
- These appliances have heating coils of high resistance.
- Generation of heat due to electric current is known as the heating effect of electricity.
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संबंधित प्रश्न
Why does the cord of an electric heater not glow while the heating element does?
Give Scientific reason
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Solve the following example.
Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
Write two devices based on the heating effect of electric current.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
The heating element of an electric iron is made up of:
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in the following figure. The current flowing in both the circuits is the same.
- Will the heat produced in both cases be equal? Explain.
- Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
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In a set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.
