Page 18 - Electrostatics 11

Grade 11 © GC Shiba
Thus, Electric intensity is equal to negative of electric potential gradient. Direction

of E is along which electric potential gradient decreases.

Equipotential surface:

Equipotential surface is such a surface on
which electric potential is the same everywhere. It

means the potential difference between any two
points on an equipotential surface is zero. We know
that p.d. is work done and hence there is no work is

done in moving the charge from one point to another on
an equipotential surface. E

❖ Electric intensity is always normal to the equipotential surface.
❖ Surface of a charge sphere is always an equipotential surface.
❖ In the region of high electric intensity, equipotential surface is closer while
in the region of low electric intensity, equipotential surface is farer.

❖ Two equipotential surfaces are never intersecting.

Electron volt: The kinetic energy gained by an electron when accelerated
through a potential difference of one volt.

i.e., 1 eV = electric work done to accelerate the electron through a p.d. of 1 volt

= K.E. gained by electron

= loss in P.E.

∴ 1 = 1.6 × 10 −19 × 1

= 1.6 × 10 −19

= 1.6 × 10 −19

Electric field: The region around a charged body up to which it exerts electric
force on any other charge is called electric field.

Electric lines of force: It is defined as the imaginary path along which a unit
positive charge would move if it were to move.

18 Electrostatics