6. A technician examines different electrical devices to determine the one that is the most
energy efficient. While conducting a test, he notes that one of these devices consumes
550 000 J of energy and loses 315 000 J at the same time. What is the energy efficiency
of this device?
A)
42.7%
B) 57.2%
D) 174.6%
C) 68.1%