Q4. The following potential differences were measured in a circuit: E is at the same potential as ground and -25 volts wrt D D is -15 volts wrt C C is -10 volts wrt B B is -30 volts wrt A What are the potentials at B, C and D wrt ground. What is the potential difference of A wrt C. What is the potential difference of C wrt A. What is the potential difference of ground wrt B i) ii) iii) iv)​