Give physical meaning of electric field.
Electric field at a point in the space around a system of charges is the force on a unit positive test charge placed at that point without disturbing the system.
Electric field is a characteristic of the system of charges and is independent of the test charge.
Field is defined at every point in space and may vary from point to point.
Electric field is a vector field, since force is a vector quantity.
The accelerated motion of charges produce electromagnetic waves which then propagate with the speed $c$.
Thus, electric and magnetic fields can be detected by their effects (forces) on charges.
Obtain the equation of electric field at a point by system of $\mathrm{'n'}$ point charges.
A thin semi-circular ring ofradius $r$ has a positive charge $q$ distributed uniformly over it. The net field $\vec E$ at the centre $O$ is
If the net electric field at point $\mathrm{P}$ along $\mathrm{Y}$ axis is zero, then the ratio of $\left|\frac{q_2}{q_3}\right|$ is $\frac{8}{5 \sqrt{x}}$, where $\mathrm{x}=$. . . . . .
Infinite charges of magnitude $q$ each are lying at $x =1,\, 2,\, 4,\, 8...$ meter on $X$-axis. The value of intensity of electric field at point $x = 0$ due to these charges will be
Four point charges $-q, +q, +q$ and $-q$ are placed on $y$ axis at $y = -2d$, $y = -d, y = +d$ and $y = +2d$, respectively. The magnitude of the electric field $E$ at a point on the $x -$ axis at $x = D$, with $D > > d$, will vary as