At the centre of a half ring of radius R = 10 cm and linear charge density 4n C m^{–1} , the potential is x π V. The value

Question

At the centre of a half ring of radius \(\mathrm{R}=10 \mathrm{~cm}\) and linear charge density \(4 \mathrm{n} \ \mathrm{C} \ \mathrm{m}^{-1}\), the potential is \(\mathrm{x} \ \pi \ \mathrm{V}\). The value of \( \mathrm{x}\) is _______. 

Answer 1

Correct answer is : 36 

Potential at centre of half ring

\(\mathrm{V}=\frac{\mathrm{KQ}}{\mathrm{R}}\)

\(\mathrm{V}=\frac{\mathrm{K} \lambda \pi \mathrm{R}}{\mathrm{R}}\)

\(\mathrm{V}=\mathrm{K} \lambda \pi \Rightarrow \mathrm{V}=9 \times 10^{9} \times 4 \times 10^{-9} \pi\)

\(\mathrm{V}=36 \pi\)