Why are shells of nuts, guava and pear gritty?

A spherical shell of radius R has a charge +Q units. The electric field due to the shell at a point

A small sphere of radius r_1 and charge q_1 is enclosed by a spherical shell of radius r_2 and charge q_2 . Show that if q_1 is positive, charge will necessarily flow from the sphere to the shell (when the two are connected by a wire) no matter what the charge q_2 on the shell is.

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 inner and outer surfaces of the shell?

The number of electrons in the valence shell of an atom cannot be ...... .

A thin metallic spherical shell of radius R carries a charge Q on its surface. A point charge Q/2 is placed at its centre C and another charge +2Q outside the shell at a distance r from the centre as shown in figure. Find the force on the charge at the centre of shell and at point A.

A spherical conduting 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. Write the expression for the electric field at a point x > r_2 from the centre of the spherical shell.

A spherical conducting shell of inner radius r_1 and outer radius r_2 has a charge Q as shown in the figure. A charge q is placed at the centre of the shell. What is the surface charge density of the inner and outer sufaces of the shell?

A thin metallic spherical shell of radius R carries a charge Q on its surface. A point charge Q/2 is placed at its centre C and another charge +2Q outside the shell at a distance r from the centre as shown in figure. Find the electric flux through the shell.

An element have two shells & have one valance electrons. identify the element.

An element have three shells & have five valance electrons. identify the element.