When a positive $q$ charge is taken from a lower potential point to a higher potential point,its potential energy will

Two point charges are located on the $x$-axis. $q_1 = -1 \ \mu C$ at $x = 0$ and $q_2 = +1 \ \mu C$ at $x = 1 \ m$. Find the work done in bringing a third charge $q_3 = +1 \ \mu C$ from infinity to $x = 2 \ m$.

At the centre of a half ring of radius $R=10 \ cm$ and linear charge density $\lambda = 4 \ nC \ m^{-1}$,the potential is $x \pi \ V$. The value of $x$ is . . . . .

Two thin circular rings of radius $R$ are placed with their axes coinciding. The charges on the two rings are $+q$ and $-q$. The potential difference between the centers of the two rings is:

Two concentric conducting spherical shells of radii $30 \, cm$ and $5 \, cm$ are charged. If the outer shell has a charge of $3 \, \mu C$ and the inner shell has a charge of $0.5 \, \mu C$,what is the electric potential on the outer spherical shell?

Three charges,each $+q$,are placed at the corners of an isosceles triangle $ABC$ with sides $BC = AC = 2a$. $D$ and $E$ are the midpoints of $BC$ and $AC$,respectively. The work done in taking a charge $Q$ from $D$ to $E$ is