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determine the resistance of a coil whose mean diameter is 2.5cm having 100 turns of manganin wire of 0.0648 cm dia. the specific resistance of manganin wire is 42/1000000 ohm-cm |
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Answer» (1) RESISTANCE of the coil R= p×L/A(2) GIVEN p= 42/1000000 ohm-cm(3) LENGTH of the wire in the coil = length of each turn× total number of turns(4)given mean diameter of the coil = 2.5 cm, HENCE radius = 1.25 cm and circumference 2×π×R=2×22/7×1.25=7.85 cm(5) length of the wire = circumference× No of turns = 7.85 × 100=785 cm(6)cross sectional area of the wire= π×d^2/4 = π×0.0648^2/4=3.297 cm^2(7)total resistance of the coil=42/1000000×785/3.29=0.01 Ohm |
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