Answer:
625 V
Step-by-step explanation:
Power is the product of voltage and current. The voltage of the solar panel can be computed from its power output and its operating current.
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P = VI . . . . . relation between power, voltage, and current
V = P/I . . . . solved for voltage
V = 25,000/40 = 625 . . . . volts
The array voltage must be 625 volts for it to supply 25 kW at 40 A.