Two identical thin rings each of radius R meters are coaxially placed at a distance R meters apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge qfrom the centre of one ring to that of other is [MP PMT 1999; AMU (Engg.) 1999]

\[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{2Q}{R}\]

\[\frac{q({{Q}_{1}}-{{Q}_{2}})(\sqrt{2}-1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\]

\[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{2Q}{R}\]

\[\frac{q({{Q}_{1}}+{{Q}_{2}})(\sqrt{2}+1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\]

Two identical thin rings each of radius R meters are coaxially placed

1.	Two identical thin rings each of radius R meters are coaxially placed at a distance R meters apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge qfrom the centre of one ring to that of other is [MP PMT 1999; AMU (Engg.) 1999]
A.	Zero
B.	\[\frac{q({{Q}_{1}}-{{Q}_{2}})(\sqrt{2}-1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\]
C.	\[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{2Q}{R}\]
D.	\[\frac{q({{Q}_{1}}+{{Q}_{2}})(\sqrt{2}+1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\]
Answer» C. \[\frac{1}{4\pi {{\varepsilon }_{0}}}.\frac{2Q}{R}\]

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