A positive point charge is released from rest at a distance $r_0$ from a positive line charge with uniform density. The speed $(v)$ of the point charge, as a function of instantaneous distance $r$ from line charge, is proportional to

821-1280

  • [JEE MAIN 2019]
  • A

    $v \propto {e^{ + r/{r_0}}}$

  • B

    $v \propto \ln \left( {\frac{r}{{{r_0}}}} \right)$

  • C

    $v \propto \sqrt {\ln \left( {\frac{r}{{{r_0}}}} \right)} $

  • D

    $v \propto \left( {\frac{r}{{{r_0}}}} \right)$

Similar Questions

A two point charges $4 q$ and $-q$ are fixed on the $x-$axis at $x=-\frac{d}{2}$ and $x=\frac{d}{2},$ respectively. If a third point charge $'q'$ is taken from the origin to $x = d$ along the semicircle as shown in the figure, the energy of the charge will

  • [JEE MAIN 2020]

Three charges, each $+q,$ are placed at the comers of an isosceles triangle $ABC$ of  sides $BC$ and $AC, 2a.$ $D$ and $E$ are the mid-points of $BC$ and $CA.$ The work done in taking a charge $Q$ from $D$ to $E$ is

  • [AIPMT 2011]

The charge $q$ is fired towards another charged particle $Q$ which is fixed, with a speed $v$. It approaches $Q$ upto a closest distance $r$ and then returns. If $q$ were given a speed $2 v$, the closest distance of approach would be

A small sphere of mass $m =\ 0.5\, kg$ carrying a positive charge $q = 110\  \mu C$ is connected with a light, flexible and inextensible string of length $r = 60 \ cm$ and whirled in a vertical circle. If a vertically upwards electric field of strength $E = 10^5 NC^{-1}$ exists in the space, The minimum velocity of  sphere required at highest point so that it may just complete the circle........$m/s$  $(g = 10\, ms^{-2})$

A particle of charge $q$ and mass $m$ is subjected to an electric field $E = E _{0}\left(1- ax ^{2}\right)$ in the $x-$direction, where $a$ and $E _{0}$ are constants. Initially the particle was at rest at $x=0 .$ Other than the initial position the kinetic energy of the particle becomes zero when the distance of the particle from the origin is

  • [JEE MAIN 2020]