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MHT CET 2026 (19 May, Shift 2) · Electric Potential & Equipotentials

Electric Potential & Equipotentials question from MHT CET 2026 (19 May, Shift 2)

Q21MHT CET 2026 · 19 MAY · SHIFT 2Difficult

Electric Potential & Equipotentials

Three concentric metallic spherical shells of radii R,3RR, 3R and 9R9R are given charges Q1,Q2Q_1, Q_2 and Q3Q_3, respectively. It is found that surface charge densities on the outer surfaces of the shells are equal. Then the ratio of charges given to shells Q1:Q2:Q3Q_1 : Q_2 : Q_3, is (Neglect the induction effects)

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Answer: (c)

  1. Neglecting induction, each shell's charge stays on it: σ=Q4πr2\sigma = \frac{Q}{4\pi r^2} equal ⇒Q∝r2\Rightarrow Q \propto r^2.
  2. Q1:Q2:Q3=R2:9R2:81R2=1:9:81Q_1 : Q_2 : Q_3 = R^2 : 9R^2 : 81R^2 = 1 : 9 : 81
  3. 1:9:81=13:3:271 : 9 : 81 = \frac{1}{3} : 3 : 27
  4. So the answer is (c).
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