In a balanced meter bridge, the segment of wire opposite to a resistance of 70 Ω is 70 cm. The unknown resistance is

Question

In a balanced meter bridge, the segment of wire opposite to a resistance of 70 Ω is 70 cm. The unknown resistance is (A) 30 Ω (B) 60 Ω (C) 90 Ω (D) 15 Ω

Tardigrade Admin · Accepted Answer

In balanced meter bridge known resistance, S=70 Ω, l=70 cm ∴ Unknown resistance, R=S((100-l/l))=(70(100-70)/70) =30 Ω

Q. In a balanced meter bridge, the segment of wire opposite to a resistance of $70 Ω$ is $70 c m$ . The unknown resistance is

$30 Ω$

$60 Ω$

$90 Ω$

$15 Ω$

In balanced meter bridge known resistance,
$S = 70 Ω, l = 70 c m$
$∴$ Unknown resistance,
$R = S (\frac{100 - l}{l}) = \frac{70 ( 100 - 70 )}{70}$
$= 30 Ω$

Q. In a balanced meter bridge, the segment of wire opposite to a resistance of 70Ω is 70cm. The unknown resistance is

30Ω

60Ω

90Ω

15Ω