AB is a wire of uniform resistance. The galvanometer G shows no current when the length AB = 20 cm and BC = 80 cm. The resistance R is equal to

Question

AB is a wire of uniform resistance. The galvanometer G shows no current when the length AB = 20 cm and BC = 80 cm. The resistance R is equal to (A) 20 Ω  (B) 80 Ω  (C) 10 Ω  (D) 40 Ω

Tardigrade Admin · Accepted Answer

For (R1/R2)=(L1/L2) ⇒ R1=(L1/L2)× R2=(20/80)× 80=20 Ω

Q. $A B$ is a wire of uniform resistance. The galvanometer $G$ shows no current when the length $A B = 20 c m$ and $BC = 80 c m$ . The resistance $R$ is equal to

$20 Ω$

$80 Ω$

$10 Ω$

$40 Ω$

For $\frac{R _{1}}{R _{2}} = \frac{L _{1}}{L _{2}}$
$\Rightarrow$ $R_{1} = \frac{L _{1}}{L _{2}} \times R_{2} = \frac{20}{80} \times 80 = 20 Ω$

Q. AB is a wire of uniform resistance. The galvanometer G shows no current when the length AB=20cm and BC=80cm. The resistance R is equal to

20Ω

80Ω

10Ω

40Ω