Q27. Two wires of same material having ratio of their lengths 1 : 3 and area of cross section 3 :1
Find the ratio between their resistances.
[Ans. 1:9
Answers
Answered by
0
Step-by-step explanation:
R
2
R
1
=
A
2
ρ
1
L
2
A
1
ρ
1
L
1
=(
L
2
L
1
)(
A
1
A
2
)
Given
L
2
L
1
=
3
2
A
2
A
1
=
2
3
⇒
R
2
R
1
=
3
2
×
3
2
R
2
R
1
R
2
R
1
=
A
2
ρ
1
L
2
A
1
ρ
1
L
1
=(
L
2
L
1
)(
A
1
A
2
)
Given
L
2
L
1
=
3
2
A
2
A
1
=
2
3
⇒
R
2
R
1
=
3
2
×
3
2
R
2
R
1
=
9
4
=
9
4
Similar questions