a metal wire is cut into several pieces the length and radius are in the ratio 1:2 compare the resistance of A and the equivalent resistance when A and B are connected in parallel
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19
here you go !
R = 2:1
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Hey dear,
◆ Answer-
Ra/Rab = 3
◆ Explaination-
# Given-
la/lb = 1/2
ra/rb = 1/2
# Solution-
Let, R1 and R2 bs resistance of two pieces A & B respectively. Let ρ be resistivity of material.
Ra = ρl / A
Ra = ρl / πr^2
Rb = ρ(2l) / π(2r)^2
Rb = ρl / 2πr^2
Rb = Ra / 2
For resistors in parallel, equivalent resistance is
1/Rab = 1/Ra + 1/Rb
1/Rab = 1/Ra + 2/Ra
1/Rab = 3/Ra
Ra/Rab = 3
Therefore, Ra/Rab = 3 .
Hope it helps...
◆ Answer-
Ra/Rab = 3
◆ Explaination-
# Given-
la/lb = 1/2
ra/rb = 1/2
# Solution-
Let, R1 and R2 bs resistance of two pieces A & B respectively. Let ρ be resistivity of material.
Ra = ρl / A
Ra = ρl / πr^2
Rb = ρ(2l) / π(2r)^2
Rb = ρl / 2πr^2
Rb = Ra / 2
For resistors in parallel, equivalent resistance is
1/Rab = 1/Ra + 1/Rb
1/Rab = 1/Ra + 2/Ra
1/Rab = 3/Ra
Ra/Rab = 3
Therefore, Ra/Rab = 3 .
Hope it helps...
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