Electric Field and Field Lines

A spherical conducting shell of inner radius $r_1$ and outer radius $r_2$ has a charge $Q$. A charge $q$ is placed at the centre of the shell.
What is the surface charge density on the (i) inner surface, (ii) outer surface of the shell?

Which type of field is produced by moving electron?

What are the differences between electric magnetic and gravitational field?

What is electric field?

What is gravitational field?

What is the difference between gravitational field and electrical field?

What are the differences between electric magnetic and gravitational field?

What is physical significance of electric field and electric dipole?

What happens if the electric field is non uniform?

What is test charge and why it is made neglibile small while testing the effect of the source charge?

What are the significance of electrical field lines?

Two conducting spheres of radii $r_1$ and $r_2$ have equal surface charge densities. The ratio of their charges is ___.

A small metal ball is suspended in an uniform electric field with the help of an insulated thread. If a high energy $\mathrm{X}$-ray beam falls on the ball, then the ball

The change in force experienced by a static charge due to an accelerated charge is not instantaneous. Explain.

Which one of the following statement is not correct about electric field?

A small sphere of mass $2\mathrm{ g}$ having charge $5\mathrm{ }\mathrm{\mu C}$ is suspended using an insulated string as given in figure. Find the angle made by string with vertical if it is placed in electric field of magnitude $2000$ $\mathrm{V} {\mathrm{m}}^{-1}$ towards right

Two conducting spheres of radii $r_1$ and $r_2$ have equal surface charge densities. The ratio of their charges is ___.

A vanishingly small point charge $q$ experiences a force $\overrightarrow{F}$ due to a source charge present in space. The ratio $\frac{\overrightarrow{F}}{q}$ is:

A much higher value of a test charge does not affect:

In order to find the electric field due to a point charge in space, the test charge should be negligibly small? Explain with reason.