COMEDK · Physics · 17. Electrostatics
Two metal spheres, one of radius \(\dfrac{R}{2}\) and the other of radius \(2 \mathrm{R}\) respectively have the same surface charge density They are brought in contact and separated. The ratio of their new surface charge densities is
- A \(2: 1\)
- B \(1: 4\)
- C \(1: 2\)
- D \(4: 1\)
Answer & Solution
Correct Answer
(D) \(4: 1\)
Step-by-step Solution
Detailed explanation
Let the surface charge density be \(\sigma\). The radii of the two spheres are \(r_1 = \dfrac{R}{2}\) and \(r_2 = 2R\). The initial charges on the spheres are \(q_1 = \sigma \times 4\pi r_1^2 = \sigma \times 4\pi \left(\dfrac{R}{2}\right)^2 = \sigma \pi R^2\) and…
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