A system with an efficiency of 74% wastes 230 W of power.What is the useful output power of the system?A 170 W B 310 W C 650 W D 880 W

To solve this problem, we need to understand that efficiency is the ratio of useful output power to the total input power. It's given by the formula:

Efficiency = (Useful output power / Total input power) * 100%

We know the efficiency and the wasted power, but we need to find the useful output power. First, we need to find the total input power. We can rearrange the formula to solve for this:

Total input power = (Useful output power / Efficiency) * 100%

But we don't know the useful output power yet. However, we know that the total input power is also equal to the sum of the useful output power and the wasted power. So we can write:

Total input power = Useful output power + Wasted power

Now we have two equations with the same unknowns, so we can solve them simultaneously. From the second equation, we can express the useful output power in terms of the total input power:

Useful output power = Total input power - Wasted power

Substituting this into the first equation gives:

Total input power = ((Total input power - Wasted power) / Efficiency) * 100%

Rearranging this equation gives:

Total input power = Wasted power / (1 - Efficiency)

Substituting the given values gives:

Total input power = 230 W / (1 - 0.74) = 230 W / 0.26 = 884.615 W

Finally, we substitute this value back into the equation for the useful output power:

Useful output power = Total input power - Wasted power = 884.615 W - 230 W = 654.615 W

So the useful output power of the system is approximately 650 W, which corresponds to option C.