Refer to the diagram. If the current through the 5 Ohm resistor is 4 amps, the voltage across A-B will be ___ volts if switches 1,3, and 4 are closed.

Refer to the diagram. If the current through the 5 Ohm resistor is 4 amps, the voltage across A-B will be ___ volts if switches 1,3, and 4 are closed.