સમાન લંબાઈ અને સમાન જાડાઈ ધરાવતા બે તારની અવરોધકતા \(6\, \Omega \,cm\) અને \(3 \,\Omega\, cm\) છે તેમને સમાંતર જોડતા સમતુલ્ય અવરોધકતા \(\rho\, \Omega \,cm\) હોય તો \(\rho\)

A \(2\)
B \(8\)
C \(6\)
D \(4\)

Verified Solution

Answer & Solution

Correct Answer

(D) \(4\)

Step-by-step Solution

Detailed explanation

\(\because\) in parallel \(R _{ net }=\frac{ R _{1} R _{2}}{ R _{1}+ R _{2}}\) \(\frac{\rho \ell}{2 A }=\frac{\rho_{1} \frac{\ell}{ A } \times \rho_{2} \frac{\ell}{ A }}{\rho_{1} \frac{\ell}{ A }+\rho_{2} \frac{\ell}{ A }}\) \(\frac{\rho}{2}=\frac{6 \times 3}{6+3}=2\) \(\rho=4\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

યાદી - I ને યાદી - II સાથે જોડો.

યાદી - I	યાદી - II
A. બોલ્ટ્ઝમેન અચળાંક	I. \([M^{-1}L^3T^{-2}]\)
B. સ્ટીફનનો અચળાંક	II. \([ML^2T^{-1}]\)
C. પ્લાન્કનો અચળાંક	III. \([ML^2T^{-2}K^{-1}]\)
D. ગુરુત્વાકર્ષણ અચળાંક	IV. \([ML^0T^{-3}K^{-4}]\)

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