In a large class, there were 220 students who wrote both the midterm and the final exam. The standard deviation of the midterm grades was 14, and that of the final exam was 20. The correlation between the grades on the midterm and the final was 0.60. Based on the least squares...
September 22, 2012
Consider a ring of radius a containing q amount of negative charges. Derive an expression for the electric field strength at a point at a distance x on the axis of this charged ring. Hence prove that at a great enough distances, the charged ring behaves like a point charge.
August 11, 2011