GATE 2022 IN – Question 59
A capacitor consists of two concentric spheres with air dielectric of permittivity $8.854\times10^{-12}$ F/m. Inner and outer radii are 10 cm and 15 cm. Its capacitance is ______ pF (two decimal places).
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 32.8 to 33.9
Explanation
C=4πεab/(b−a). Substituting a=0.10 m, b=0.15 m and ε=8.854×10⁻¹² F/m gives 33.3795 pF, rounding to **33.38 pF**.