Some equipotential surfaces are shown. The electric field at any point is

A current of $10 \mathrm{A}$ is passing through a long wire which has a semicircular loop of the radius $20 \mathrm{cm}$ as shown in the figure. Magnetic field produced at the centre of the loop is:

Figure shows three arrangements of electric field lines. In each arrangement, a proton is released from rest at point A and then accelerated through point B by the electric field. Points A and B have equal separations in the three arrangements. If $p_1,p_2$ and $p_3$ are linear momentum of the proton at point B in the three arrangement respectively, then

An electron is placed on $X$-axis where the electric potential depends on $x$ as shown in figures (the potential does not depend on $y$ and $z$ ). What is the electric force on the electron?