Ring charge This was left as an exercise. Consider the following ring of charge with radius K and total charge Q. Show that the expression (or the integral) for the electric field at point P is given by E₂ kQz (2²+R²)3/2 Disc charge Now let's see how we can use the above result to find the electric field due to a charged disc. Typically for a disc you would need to evaluate a 2D integral, but if you image the disc as an accumulation of ring charges, the integral is effectively 1D¹. a-area charge density R ¹Hint: Think about how you would express dQ= adA can be expressed in terms of dR, i.e. how would A and R relate (hence dA with dR).

Ring charge This was left as an exercise. Consider the following ring of charge with radius K and total charge Q. Show that the expression (or the integral) for the electric field at point P is given by E₂ kQz (2²+R²)3/2 Disc charge Now let's see how we can use the above result to find the electric field due to a charged disc. Typically for a disc you would need to evaluate a 2D integral, but if you image the disc as an accumulation of ring charges, the integral is effectively 1D¹. a-area charge density R ¹Hint: Think about how you would express dQ= adA can be expressed in terms of dR, i.e. how would A and R relate (hence dA with dR).