JEE Mains · Physics · STD 12 - 2. Electric potential and capacitance
Within a spherical charge distribution of charge density \(\rho \left( r \right)\), \(N\) equipotential surfaces of potential \({V_0},{V_0} + \Delta V,{V_0} + 2\Delta V,\)\(.....{V_0} + N\Delta V\left( {\Delta V > 0} \right),\) are drawn and have increasing radii \(r_0, r_1, r_2,......r_N\), respectively. If the difference in the radii of the surfaces is constant for all values of \(V_0\) and \(\Delta V\) then
- A \(\rho \left( r \right) = \) constant
- B \(\rho \left( r \right) \propto \frac{1}{{{r^2}}}\)
- C \(\rho \left( r \right) \propto \frac{1}{r}\)
- D \(\rho \left( r \right) \propto r\)
Answer & Solution
Correct Answer
(C) \(\rho \left( r \right) \propto \frac{1}{r}\)
Step-by-step Solution
Detailed explanation
As we know electric field, \(E = \frac{{ - dv}}{{dr}}\) \(E=\) constant \(\therefore \) \(dv\) and \(dr\) same \( \Rightarrow \,\rho \propto \frac{1}{r}\)
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