Norbu's mobile phone battery was very low. When he searched for his charger, he found that he had forgotten to take his mobile charger with him. He had two thin copper wires with him. Can he use these wires to charge his mobile phone by inserting them directly to the socket? Why?

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.