Electrostatics questions | form five Physics

Define the following terms

1. capacitance
2. Charge density
3. Equipotential surface.

By using coulomb`s law of electrostatics, derive an expression for the electric field strength E, due to a point charge if the material is surrounded by a material of permittivity , and hence show how it relates with charge density .

Describe the structure and the mode of action of a simplified version of the Van de Graaff generator.

Identify any three factors on which the capacitance of parallel plate capacitor depends.

A proton of mass 16.7x10^-28kg falls through a distance of 2.5cm in a uniform electric field of magnitude 2.65x10⁴V/m. Determine the time of fall if the air resistance and the acceleration due to gravity , g are neglected.

A parallel plate capacitor is made of a paper sheet required to construct a capacitance of 15µF, if its relative permittivity is 2.5.

Differentiate electric potential from electric potential difference.

Sketch a graph of variation of electrical potential from the centre of a hollow charged conducting sphere of radius r, up to infinity. Explain the shape of the graph.

Two bodies A and B are 0.1m apart. A point charge of 3x10^-3µC is placed at A and a point charge of -1x10^-8µC is placed at B. C is the point on the straight line between A and B, where the electric potential is zero. Calculate the distance between A and C.

A square ABCD has each side of 100cm. Four point charges of +0.04µC,-0.05µC, +0.06µC and +0.05µC are placed at A, B, C and D respectively. Calculate the electric potential at the centre of the square.