Two capacitors having a capacity of 30 nf and 45 nfare connected in a string and connected to a 220 v voltage source. calculate the voltage between the condenser surfaces if they were disconnected from the voltage source and connected parallel.

Find an expression for the electric field e⃗ at the center of the semicircle. hint: a small piece of arc length δs spans a small angle δθ=δs /r, where r is the radius. express your answer in terms of the variables q, l, unit vectors i^, j^, and appropriate constants.