An electric press consumes 120 kJ of energy in 5 minutes, with a current of 2 A flowing through it. Calculate the electric potential at which the press operates.
Answer (2)
Power = joules/second (watts)
(120,000 joules/5 minutes) x (minute/60 seconds) = 400 watts
Power dissipated by a component in an electrical circuit =
(current through it) x (potential difference across it).
400 watts = (2 amperes) x V
V = 400 watts / 2 amperes = 200 volts
Note: That's the potential DIFFERENCE between the terminals of the machine, NOT the "potential at which it operates".
The electric potential at which the electric press operates is calculated to be 200 volts. This is found using the power formula relating energy, time, current, and voltage. Therefore, using 120 kJ of energy over 5 minutes with a current of 2 A yields this potential difference.
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