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What is short circuiting? State one factor/condition that can lead to it. Name a device in the household that acts as a safety measure for it. State the principle of its working. |
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Answer» Short circuiting: When electric circuit offers very low resistance to the flow of current through it, the current increases heavily and the circuit is said to be short circuited. It occurs when live wire touches the neutral wire. This happens due to the damage in insulation of the power lines. Safety measure device: Fuse. Working principle of fuse: It works on the heating effect of electric current or Joule’s law of heating. According to this law, the heat produced in a resistor is directly proportional to the (i) square of current for a given resistance. (ii) resistance for a given current and (iii) time for which the current flows through the resistor. H = I2Rt So, when current in the circuit increases, the wire with low melting point in it melts to the heat generated. Hence, the circuit breaks and electrical devices and appliances are saved. |
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