In infinite long uniformly charged string is placed along $z-$ axis. Its linear charge density is $\lambda $. A point charge $q$ is moved from position $(a, 0, 0)$ to $(2a, 0, 0)$ then work done will be

  • A

    $ - \frac{{K\lambda }}{a}\left( q \right)$

  • B

    $\frac{{K\lambda q}}{{2a}}\,\ln \,\left( 2 \right)$

  • C

    $ - 2k\lambda q\,(\ln \,2)$

  • D

    $ - \frac{{2k\lambda q}}{a}\,(\ln \,2)$

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