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MHT CET 2023 (11 May, Shift 2) · Capacitance of a Conductor

Capacitance of a Conductor question from MHT CET 2023 (11 May, Shift 2)

Q10MHT CET 2023 · 11 MAY · SHIFT 2Medium

Capacitance of a Conductor

Two spherical conductors of capacities 3 μF3\ \mu\text{F} and 2 μF2\ \mu\text{F} are charged to same potential having radii 3 cm3\text{ cm} and 2 cm2\text{ cm} respectively. If 'σ1\sigma_1 ' and 'σ2\sigma_2' represent surface density of charge on respective conductors then σ1σ2\frac{\sigma_1}{\sigma_2} is

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Answer: (c)

  1. Same potential: Q=CVQ = CV, and C∝rC \propto r, so Q∝rQ \propto r.
  2. σ=Q4πr2∝rr2=1r\sigma = \frac{Q}{4\pi r^2} \propto \frac{r}{r^2} = \frac{1}{r}
  3. σ1σ2=r2r1=23\frac{\sigma_1}{\sigma_2} = \frac{r_2}{r_1} = \frac{2}{3}
  4. So the answer is (c) 23\frac{2}{3}.
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