If the current in the circuit above is 10 amps and the resistance is 3 ohms, what is the voltage?

It's really difficult to make out the circuit above. Quite frankly, your

question leaves me to wonder how far 'above' it may be.

The best I can do will be to try and fabricate an answer based on the

information given in the text of the question, augmented only by my own

training, chutzpah, and life experiences.

If the circuit ... wherever it is ... consists entirely of the single 3-ohm

resistance and no other components, and the current through the

resistance is 10 Amperes, then

Voltage = (Current) x (resistance) = 30 volts.