JEE Mains · Physics · STD 12 - Electric potential and capacitance
- JEE Mains 2019
- Hard
- MCQ
Two electric dipoles \(A, B\) with respective dipole moments \(\overrightarrow {{d_A}} = - 4\,qa\,\hat i\) and \(\overrightarrow {{d_B}} = 2\,qa\,\hat i\) are placed on the \(x-\) axis with a separation \(R\), as shown in the figure. The distance from \(A\) at which both of them produce the same potential is

Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(\frac{{\sqrt 2 R}}{{\sqrt 2 + 1}}\)
Step-by-step Solution
Detailed explanation
\(v_{1}=v_{2}\)
\(\frac{\mathrm{k}(2 \mathrm{qa})}{\mathrm{x}^{2}}=\frac{\mathrm{k}(4 \mathrm{qa})}{(\mathrm{R}-\mathrm{x})^{2}}\)
\(R-x=\sqrt{2} x\)
\(x=\frac{R}{\sqrt{2}+1}\)
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