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JEE Main 2021 (25 Jul, Shift 2) · Kirchhoff's Laws & Measuring Instruments

Kirchhoff's Laws & Measuring Instruments question from JEE Main 2021 (25 Jul, Shift 2)

Q120JEE Main 2021 · 25 JUL · SHIFT 2Medium

Kirchhoff's Laws & Measuring Instruments

A 16 Ω\Omega wire is bent to form a square loop. A 9V supply having internal resistance of 1Ω\Omega is connected across one of its sides. The potential drop across the diagonals of the square loop is _______________ ×\times 10−-1 V

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

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Answer: 45

ABCD4 Ω4 Ω4 Ω4 Ω9 V, 1 Ω
  1. Each side =4 Ω= 4\ \Omega. Across side AB: 4∥12=3 Ω4 \parallel 12 = 3\ \Omega.
  2. I=93+1=94I = \frac{9}{3 + 1} = \frac{9}{4} A, so VAB=94×3=6.75V_{AB} = \frac{9}{4} \times 3 = 6.75 V.
  3. Current in path A–D–C–B: 6.7512=0.5625\frac{6.75}{12} = 0.5625 A.
  4. Diagonal AC: VAC=0.5625×8=4.5V_{AC} = 0.5625 \times 8 = 4.5 V (same for BD).
  5. So the answer is 45×10−145 \times 10^{-1} V.
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