JEE Mains · Physics · STD 12 - 1. Electric charges and fields
Three point charges \(q,-2 q\) and \(2 q\) are placed on \(x\)-axis at a distance \(x=0, x=\frac{3}{4} R\) and \(x=R\) respectively from origin as shown. If \(q =2 \times 10^{-6}\,C\) and \(R =2\,cm\), the magnitude of net force experienced by the charge \(-2 q\) is .......... \(N\)
- A \(5442\)
- B \(5440\)
- C \(5448\)
- D \(5475\)
Answer & Solution
Correct Answer
(B) \(5440\)
Step-by-step Solution
Detailed explanation
\(F _{ BA }=\frac{ Kq (2 q )}{\left(\frac{3}{4} R \right)^2}=\frac{32 Kq ^2}{9 R ^2}\) \(F _{ BC }=\frac{ K (2 q )(2 q )}{\left(\frac{ R }{4}\right)^2}=\frac{64 Kq ^2}{ R ^2}\) \(F _{ B }= F _{ BC }- F _{ BA }=\frac{544 Kq ^2}{9 R ^2}\)…
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