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JEE Main 2024 (5 Apr, Shift 1) · Kirchhoff's Laws & Measuring Instruments

Kirchhoff's Laws & Measuring Instruments question from JEE Main 2024 (5 Apr, Shift 1)

Q74JEE Main 2024 · 5 APR · SHIFT 1Difficult

Kirchhoff's Laws & Measuring Instruments

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of 1/θ1/\theta vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is _________ ×10−1 A/\times 10^{-1}\text{ A}/ division. [The source has emf 2 V2\text{ V}]

Figure

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

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Answer: 5

  1. θ=IK\theta = \frac{I}{K} with I=ER+GI = \frac{E}{R + G}, so 1θ=KER+KGE\frac{1}{\theta} = \frac{K}{E}R + \frac{KG}{E}
  2. Slope =2−16−2=14=KE= \frac{2 - 1}{6 - 2} = \frac{1}{4} = \frac{K}{E}
  3. K=24=0.5 A/div=5×10−1 A/divK = \frac{2}{4} = 0.5\text{ A/div} = 5 \times 10^{-1}\text{ A/div}
  4. Answer: 5
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