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One conducting wire of length 1 m is cut into two unequal part P and Q respectively. Now, part P is stretched to double its length. Let the modified wire be R. If the resistance of the R and Q wires are same, then calculate the length of P and Q wires. |
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Answer» udent,◆ Answer -p = 20 cmq = 80 CM● Explanation -# Given -l = 1 m = 100 cm# Solution -Let p and q represents lengths of two segments.When P is stretched to double its length, its cross-sectional area will be halved. Resistance of stretched WIRE P is -Rp = ρ.(2P)/(A/2)Rp = 4ρp/ALength of wire Q will be q = 100-p. So now resistance of wire Q is -Rq = ρ.(100-p)/AGiven that,Rp = Rq4ρp/A = ρ.(100-p)/A4p = 100-p5p = 100p = 20 cmNow,q = 100-pq = 100-20q = 80 cmThus, length of P and Q is 20 cm and 80 cm respectively.Thanks dear... |
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