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JEE Main 2026 (24 Jan, Shift 2) · Wheatstone Bridge & Metre Bridge

Wheatstone Bridge & Metre Bridge question from JEE Main 2026 (24 Jan, Shift 2)

Q17JEE Main 2026 · 24 JAN · SHIFT 2Medium

Wheatstone Bridge & Metre Bridge

In a meter bridge experiment to determine the value of unknown resistance, first the resistances 2 Ω2\ \Omega and 3 Ω3\ \Omega are connected in the left and right gaps of the bridge and the null point is obtained at a distance l cml\text{ cm} from the left. Now when an unknown resistance x Ωx\ \Omega is connected in parallel to 3 Ω3\ \Omega resistance, the null point is shifted by 10 cm to the right of wire. The value of unknown resistance xx is

‾ Ω\underline{\qquad}\ \Omega.

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

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Answer: 6

  1. Initially 23=l100−l⇒l=40 cm\dfrac{2}{3} = \dfrac{l}{100-l} \Rightarrow l = 40\text{ cm}.
  2. New null point at 50 cm, so the right gap becomes 2 Ω2\ \Omega.
  3. 3x3+x=2⇒x=6\dfrac{3x}{3+x} = 2 \Rightarrow x = 6.
  4. x=6 Ωx = 6\ \Omega.
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