A resistance wire made from German silver has a resistance of 4.25 ohm. Calculate the resistance oi another wire, made from the same material such that its length increased by 4times and area decreased by 3times.

Asked by sudhma3u | 31st May, 2019, 07:12: AM

Expert Answer:

Initial resistance R=4.25Ω
R equals fraction numerator rho l over denominator A end fraction
If length is made 4 times, the new length would be 
l to the power of apostrophe equals 4 l
Area is made one- third of its initial value , new area would be
A to the power of apostrophe equals A over 3
N e w space r e s i s tan c e space i s space g i v e n space b y
R to the power of apostrophe equals fraction numerator rho l to the power of comma over denominator A to the power of comma end fraction
R to the power of apostrophe equals fraction numerator rho 4 l over denominator begin display style bevelled A over 3 end style end fraction
R to the power of apostrophe equals fraction numerator 12 rho l over denominator A end fraction
R to the power of apostrophe equals 12 R
O n space s u b s t i t u t i n g space t h e space v a l u e space o f space R
R to the power of apostrophe equals 12 cross times 4.25
R to the power of apostrophe equals 12 cross times 4.25
R to the power of apostrophe equals 51 capital omega

Answered by Utkarsh Lokhande | 31st May, 2019, 08:19: AM