A cylindrical capacitor has coaxial cylinders of length 15 cm and radii 1.5 cm and 1.4 cm. The outer cylinder is earthed and the inner has charge 3.5 μC. Find the potential of the inner cylinder in volts.
Physics · Capacitor
JEE Advanced

Question

A cylindrical capacitor has coaxial cylinders of length 15 cm and radii 1.5 cm and 1.4 cm. The outer cylinder is earthed and the inner has charge 3.5 μC. Find the potential of the inner cylinder in volts.

Physics · Capacitor

G1 Physics · Accepted Answer

Capacitance of a coaxial capacitor is C=2π ε₀L/ln(b/a), with a=0.014 m, b=0.015 m, L=0.15 m. This gives C≈1.21×10⁻¹⁰ F. Hence V=Q/C=(3.5×10⁻⁶)/(1.21×10⁻¹⁰)≈2.89×10⁴ V. Numeric answer: 28900.