YASH
CLASSES
8. ELECTRIC CURRENT
69. A piece of wire
is drawn by pulling
it until
its
length is triple.
Compare the new
resistance with original .
70. A piece of wire
is drawn by pulling
it until
its
length is half.
Compare the new
resistance with original .
71. A piece
of wire is drawn
by pulling it until
its
length is ¼ .
Compare the new
resistance with original .
72. A wire of
resistance 10Ω
is drawn out so
that
its length is
density is thrice
its original
length
. Calculate its new
resistance . [
if
density
and resistance remain
unchanged ]
73. A wire
of resistance 20Ω is
drawn out so
that
its length is
density is thrice
its original
length
. Calculate its new
resistance . [
if
density
and resistance remain
unchanged ]
74. A wire of
resistance 25Ω
is drawn out so
that
its length is
density is twice
its original
length
. Calculate its new
resistance . [
if
density
and resistance remain
unchanged ]
75. A wire
of resistance 50 Ω is
drawn out so
that
its length is
density is half
its original
length
. Calculate its new
resistance . [
if
density
and resistance remain
unchanged ]
76. A wire of
resistance 30 Ω is
drawn out so
that
its length is
density is ¼ its
original
length
. Calculate its new
resistance . [
if
density
and resistance remain
unchanged ]