The linear charge density on a dielectric ring of radius $R$ varies with $\theta $ as $\lambda \, = \,{\lambda _0}\,\cos \,\,\theta /2,$ where $\lambda _0$ is constant. Find the potential at the centre $O$ of ring. [in volt]

  • A

    $\lambda _0\,\,R$

  • B

    $\frac {\lambda _0\,R}{2}$

  • C

    $\frac {\lambda _0}{4\pi \epsilon _0R }$

  • D

    zero

Similar Questions

Which of the following statements is true about the flow of electrons in an electric circuit?

  • [KVPY 2012]

A charge of total amount $Q$ is distributed over two concentric hollow spheres of radii $r$ and $R ( R > r)$ such that the surface charge densities on the two spheres are equal. The electric potential at the common centre is

  • [JEE MAIN 2020]

Variation in electric potential is maximum if one goes

If the potential at the centre of a uniformly charged hollow sphere of radius $R$ is $V$ then electric field at a distance $r$ from the centre of the sphere is $(r > R)$

Four charges $ + Q,\, - Q,\, + Q,\, - Q$ are placed at the corners of a square taken in order. At the centre of the square