Please answer Q15,,please
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resistance,R = resistivity ×l/a
here a=pie×r^2
now lenth is doubled so
length of another wire=2l
area of another wire= pie ×r^2/4 =a/4
so resistance of another wire
= resistivity × 2l/a/4
=resistivity ×8l/a
=8R [ because r= resistivity ×l/a]
here a=pie×r^2
now lenth is doubled so
length of another wire=2l
area of another wire= pie ×r^2/4 =a/4
so resistance of another wire
= resistivity × 2l/a/4
=resistivity ×8l/a
=8R [ because r= resistivity ×l/a]
KingAgr:
plz mark brainliest
Answered by
2
option D is correct
R = resistivity*L/A
= resistivity*L/pi*r^2
now if L =2L and r=1/2r
then
R=resistivity*2L/pi*r^2*1/4
=8*resistivity*L/pi*r^2
=8R
hence D is correct
R = resistivity*L/A
= resistivity*L/pi*r^2
now if L =2L and r=1/2r
then
R=resistivity*2L/pi*r^2*1/4
=8*resistivity*L/pi*r^2
=8R
hence D is correct
how can L=2L??
New L = 2* previous value. . it means that
Sry kvn murty but if you have denoted lenth of first wire as L then you can't denote length of second wire as L
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