The device is 50% efficient. Which equation is correct? A input energy = useful output energy ÷ 2 B useful output energy =wasted output energy ÷ 2 C wasted output energy = useful output energy D wasted output energy = useful output energy ÷ 2

C - wasted output energy = useful output energy

Explanation:

Useful output + wasted output ALWAYS equals input energy. If the device is 50% efficient, that means that 50% of the input energy is converted into useful output energy, and 50% is converted to wasted output energy. The wasted output energy is equal to the useful output energy.

the entire statement is true and correct.  

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