Physics · Current Electricity

JEE Main 2026 — 24 January, Morning Shift — Question 35

Two resistors 2Ω2 \Omega and 3Ω3 \Omega are connected in the gaps of bridge as shown in figure. The null point is obtained with the contact of jockey at some point on wire XY . When an unknown resistor is connected in parallel with 3Ω3 \Omega resistor, the null point is shifted by 22.5 cm toward Y . The resistance of unknown resistor is Ω\Omega.

Question figure
  1. Option A:

    3

  2. Option B:

    2

    Correct
  3. Option C:

    4

  4. Option D:

    1

Answer: B

Step-by-step solution

Initially, 23=x100−x\frac{2}{3}=\frac{\mathrm{x}}{100-\mathrm{x}} ⇒x=40 cm\Rightarrow \mathrm{x}=40 \mathrm{~cm} Now when ' RR ' connected in parallel 23R3+R=40+22.560−22.5=62.537.5\frac{2}{\frac{3 R}{3+R}}=\frac{40+22.5}{60-22.5}=\frac{62.5}{37.5} ∴R=2Ω\therefore \mathrm{R}=2 \Omega

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Physics
Chapter
Current Electricity
Topic
Combination of Resistors and cells, Wheatstone Bridge
Two resistors 2 Ω and 3 Ω are connected in the gaps of bridge as… | JEE Main 2026 PYQ with Solution · DhiX AI