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An electric fan becomes warm if used continuously for longer time. This happens due to:
the slow rotation of the fan
the fast rotation of the fan
heating effect of the current flowing through the fan
the high temperature during the summer
heating effect of the current flowing through the fan
An electric fan becomes warm due to the Joule heating effect. As electric current flows through the copper windings of the fan's motor, it encounters resistance, leading to the conversion of electrical energy into thermal energy.
An electric fan becomes warm due to the Joule heating effect. As electric current flows through the copper windings of the fan's motor, it encounters resistance, leading to the conversion of electrical energy into thermal energy.
Think of it like a water pipe that is slightly constricted; the friction of water pushing against the narrow walls creates heat, just as electrons pushing against the resistance of the copper wire create heat in the fan motor.
HI┬▓с┤┐с╡А: Heat (H) equals I-squared (I┬▓) times Resistance (R) times Time (T).
H=I2Rt тАФ where H is heat energy, I is current, R is resistance, and t is time.
According to Joule's law of heating, the heat produced in a conductor is directly proportional to the square of the current (I2), the resistance (R), and the time (t) for which the current flows. As the fan runs, the internal motor coil's electrical resistance dissipates energy as heat, which accumulates over continuous usage.
Electrical resistance is the inherent property that causes heating.
Copper wire is used in motor coils because it has low resistance, but it is not zero.
Heat dissipation is an inevitable byproduct of energy conversion in resistive circuits.
Energy loss in the form of unwanted heat.
Potential wear and tear on insulation materials due to prolonged thermal stress.
Electric motors
Electric heaters
Incandescent bulbs
Resistance (R) depends on the material, length, and cross-sectional area of the wire.
Option A and B are incorrect because fan rotation speed affects mechanical output and air displacement, but is not the primary cause of heat generation compared to electrical resistance.
Option D is incorrect because ambient temperature may affect heat dissipation, but it is not the root cause of the fan's internal heat generation.
C is correct тАФ Continuous operation of an electric motor results in heat production due to the resistance of the internal wiring as per Joule's Law.
In competitive exams, always link 'heating effect' questions directly to I2R losses, which is a common principle behind fuses, electric toasters, and irons.
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