Two charges each of $1\;coulomb$ are at a distance $1\,km$ apart, the force between them is
$9 \times {10^3}\;Newton$
$9 \times {10^{ - 3}}\;Newton$
$1.1 \times {10^{ - 4}}\;Newton$
${10^4}\;Newton$
Point charges $ + 4q,\, - q$ and $ + 4q$ are kept on the $x - $axis at points $x = 0,\,x = a$ and $x = 2a$ respectively, then
An infinite number of point charges, each carrying $1 \,\mu C$ charge, are placed along the y-axis at $y=1\, m , 2\, m , 4 \,m , 8\, m \ldots \ldots \ldots \ldots \ldots$
The total force on a $1 \,C$ point charge, placed at the origin, is $x \times 10^{3}\, N$. The value of $x$, to the nearest integer, is .........
[Take $\left.\frac{1}{4 \pi \epsilon_{0}}=9 \times 10^{9} \,Nm ^{2} / C ^{2}\right]$
Two equal negative charges are fixed at the points $ [0, a ]$ and $[0, -a]$ on the $y-$ axis. A positive charge $Q$ is released from rest at the points $[2a, 0]$ on the $x-$axis . The charge $Q$ will
Write value of Coulombian constant $k$ in $SI$ unit.
A charged particle with charge $q$ and mass $m$ starts with an initial kinetic energy $K$ at the middle of a uniformly charged spherical region of total charge $Q$ and radius $R$ . $q$ and $Q$ have opposite signs. The spherically charged region is not free to move . The value of $K_0$ is such that the particle will just reach the boundary of the spherically charged region. How much time does it take for the particle to reach the boundary of the region.