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A 4 ohm resistance wire is doubled on it calculate the new resistance of the wire |
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Answer» <P>We consider wire is DOUBLED on it means to fold the length of wire. It means its length will get half and area of CROSS section will get doubled. ∴ Let the resistance of the wire originally 'R' of length 'L' and area of cross-section 'A' with resistivity of material is 'p', Then R = p l/A = 4Ω Now, for new arrangement, p' = p l' = l / 2 A' = 2A Thus, R' = p' l'/A' = p (l /2) ÷ 2A = !/4 (p l / A) = 1/4R = 1/4 × 4 = 1Ω. |
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