ElectrostaticsHard
Question
A conducting sphere of radius 10cm is charged with 10μC. Ancher unchared spher of bradius 20 cm is allowed to toch it for some time. After that if the spheres are separated, Then surface density of charge on the spheres will be in the ratio of
Options
A.1 : 1
B.2 : 1
C.1 : 3
D.4 : 1
Solution
Let the common potential after the touch is V.So, applying conservation of charge
10 × 10-6 = V × C1 + V × C2
Charge on first sphere
= C1V =
× C1
Charge on second sphere
= C2V = × C2
Charge densities are,
and their ratio =
= 2 : 1
[Capacity of spherical capacitor = 4π∈0R]
10 × 10-6 = V × C1 + V × C2
Charge on first sphere
= C1V =
× C1Charge on second sphere
= C2V =
× C2 Charge densities are,
and their ratio =
= 2 : 1[Capacity of spherical capacitor = 4π∈0R]
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