Questions 11 through 15 feier to the following. A 3.0-ohm resistor, an unknown resistor, R, and two ammeters, A, and A,, are connected as shown below with a 12-volt source. Ammeter A, reads a current of 5.0 amperes. 5.0A A2 A. 12 V 3.0 0 11) Determine the equivalent resistance of the circuit shown. 12) Calculate the current measured by ammeter 4, in the diagram shown. 13) Calculate the resistance of the unknown resistor, R in the diagram shown