Electric fields and Coulomb's lawEdexcel International A Level Physics: Mind map

Exam questions on Electric fields and Coulomb's law

1. Two very small charged spheres, A and B, carry charges of +2.0 nC and +5.0 nC respectively. They are held 4.0 cm apart in air, so they may be treated as point charges in a vacuum.
   Calculate the magnitude of the force between the spheres when they are 4.0 cm apart.2 marks
2. In a simple model of a hydrogen atom, an electron moves in a circular orbit around a single proton. The separation of the two particles is 5.3 × 10⁻¹¹ m. The magnitude of the charge on each particle is 1.60 × 10⁻¹⁹ C.
   Calculate the force on the electron due to the proton and state its direction.2 marks
3. A small metal sphere carries a charge of +6.0 nC. Point P is 0.30 m from the centre of the sphere, in air.
   Calculate the electric field strength at P and state its direction.3 marks