a wire of length 'l' cross-sectional area 'A' and resistance 'R' is doubled o itself. then find its new resistance.

Asked by Dave Agresha | 27th May, 2015, 09:08: AM

Expert Answer:

begin mathsize 14px style straight R equals ρl over straight A therefore straight R subscript 1 over straight R subscript 2 equals fraction numerator straight l subscript 1 divided by straight A subscript 1 over denominator straight l subscript 2 divided by straight A subscript 2 end fraction equals fraction numerator straight l subscript 1 straight A subscript 2 over denominator straight l subscript 2 straight A subscript 1 end fraction space space space space space space space space space space because straight l subscript 2 equals 1 half straight l subscript 1 space space space space space straight A subscript 2 equals 2 straight A subscript 1 therefore straight R subscript 1 over straight R subscript 2 equals fraction numerator straight l subscript 1 space 2 straight A subscript 1 over denominator left parenthesis 1 divided by 2 right parenthesis straight l subscript 1 space straight A subscript 1 end fraction straight R subscript 1 over straight R subscript 2 equals 4 therefore straight R subscript 2 equals straight R subscript 1 over 4 end style

Answered by Faiza Lambe | 27th May, 2015, 02:41: PM

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