Question 32

A cylindrical capacitor has two co-axial cylinders of length 15 cm and radii 1.5 cm and 1.4 cm. The outer cylinder is earthed and the inner cylinder is given a charge of 3.5 µC. Determine the capacitance of the system and the potential of the inner cylinder. Neglect end effects (i.e., bending of field lines at the ends).

Answer

Length of a co-axial cylinder, l = 15 cm = 0.15 m

Radius of outer cylinder, r_{1} = 1.5 cm = 0.015 m

Radius of inner cylinder, r_{2} = 1.4 cm = 0.014 m

Charge on the inner cylinder, q = 3.5 µC = 3.5 x 10 ^{- 6} C

Capacitance of a co-axial cylinder of radii r_{1} and r_{2} is

given by the relation,

Where,

∈_{0} = Permittivity of free space = 8.85 x 10^{-12} x N^{-1}m^{-2}C^{2}

Potential difference of the inner cylinder is given by,

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Mini
2019-03-04 18:31:13

Right ans very helpful

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