JEE Mains · Physics · STD 12 - Electric potential and capacitance
- JEE Mains 2020
- Hard
- MCQ
Ten charges are placed on the circumference of a circle of radius \(R\) with constant angular separation between successive charges. Alternate charges \(1,3,5,7,9\) have charge \((+q)\) each, while \(2,4,6,8,10\) have charge \((-q)\) each. The potential \(V\) and the electric field \(E\) at the centre of the circle are respectively (Take \(V =0\) at infinity \()\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) \(V =0, E =0\)
Step-by-step Solution
Detailed explanation
Sol. Potential of centre \(= V =\quad \Sigma\left(\frac{ kq }{ R }\right)\)
\(V _{ C }=\frac{ K (\Sigma q )}{ R }\)
\(V _{ C }=\frac{ K (0)}{ R }=0\)
Electric field at centre \(\overrightarrow{ E }_{ B }=\Sigma \overrightarrow{ E }\)
Let \(E\) be electric field produced by each charge at the centre, then resultant electric field will be
\(E _{ C }=0,\) since equal electric field vectors are acting at equal angle so their resultant is equal to zero.
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