Question

A capacitor is made from two hollow, coaxial, iron cylinders, one inside the other. The inner cylinder is negatively charged and the outer is positively charged; the magnitude of the charge on each is 10.0 pC. The inner cylinder has a radius of 0.50 mm, the outer one has a radius of 5.00 mm, and the length of each cylinder is 18.0 cm. (a) What is the capacitance? (b) What applied potential difference is necessary to produce these charges on the cylinders?

Short answer

The Capacitance is $4.35\times {10}^{-12}F$.

The electric voltage required to keep this charge is given by 2.3V.

Step-by-step solution

Step 1:

Given $Q=10\times {10}^{-12}C,r_a=0.5mm,r_a=0.5\times {10}^{-3}m,L=180cm$

The capacitance of the coaxial cylinder according is given

Substitute in equation(1)

The electric voltage required to keep this charge is given by

Step 2:

The Capacitance is$4.35\times {10}^{-12}F$.

The electric voltage required to keep this charge is given by 2.3V.