What do fuel cells, batteries and, solar cells have in common a. the all produce static electricity b. they are all sources of direct current c. they are all sources of alternating current d. can all be used to power automobiles

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.