I have just started to learn these things(electric field strength, electric potnential energy and electric potential). I am not very clear about what they are. I would like to ask a few questions here. Why is electric field strength somtimes +ve but sometimes -ve? what does each of them imply? What is electric potential energy? Is it a vector or scalar? does it increase or decrease when it comes closer to a charged object? What is electirc potential energy and electric potential? Are they related to the electric field strength? Why is electirc field strength equal to zero inside a charged metal sphere? May anyone answer my questions? Thank you.