When two resistance R₁ and R₂ connected in series and introduced into the left gap of a meter bridge and a resistance of 10 Ω is introduced into the right gap, a null point is found at 60 cm from left side. When R₁ and R₂ are connected in parallel and introduced into the left gap, a resistance of 3 Ω is introduced into the right gap to get null point at 40 cm from left end. The product of R₁ R₂ is ____________ Ω² Numerical answer type. Work it out, then open the answer.

Answer: 30. Series: (R₁+R₂)/(10) = 60/40 ⇒ R₁ + R₂ = 15 Ω. Parallel: Rp/3 = 40/60 ⇒ Rp = 2 Ω. Rp = (R₁R₂)/(R₁+R₂) ⇒ R₁R₂ = 2 × 15. R₁R₂ = 30 Ω².

When two resistance R₁ and R₂ connected in series and introduced into… | JEE Main 2023 (29 Jan, Shift 2)

Q45JEE Main 2023 · 29 JAN · SHIFT 2Medium

Wheatstone Bridge & Metre Bridge

When two resistance $R_1$ and $R_2$ connected in series and introduced into the left gap of a meter bridge and a resistance of 10 $\Omega$ is introduced into the right gap, a null point is found at 60 cm from left side. When $R_1$ and $R_2$ are connected in parallel and introduced into the left gap, a resistance of 3 $\Omega$ is introduced into the right gap to get null point at 40 cm from left end. The product of $R_1 R_2$ is ____________ $\Omega^{2}$

Numerical answer type. Work it out, then open the answer.

Show answer and solution

Answer: 30

Series: $\dfrac{R_1+R_2}{10} = \dfrac{60}{40} \Rightarrow R_1 + R_2 = 15\ \Omega$ .
Parallel: $\dfrac{R_p}{3} = \dfrac{40}{60} \Rightarrow R_p = 2\ \Omega$ .
$R_p = \dfrac{R_1R_2}{R_1+R_2} \Rightarrow R_1R_2 = 2 \times 15$ .
$R_1R_2 = 30\ \Omega^2$ .

Report a mistake

Wheatstone Bridge & Metre Bridge question from JEE Main 2023 (29 Jan, Shift 2)

More questions on Wheatstone Bridge & Metre Bridge