An electric motor has an input power $P_{in}$, useful output power $P_{out}$ and efficiency $\eta$. What is the power lost in the motor?
- A$\eta P_{in}$
- B$\left(\frac{1}{\eta}-1\right)P_{in}$
- C$\eta P_{out}$
- D$\left(\frac{1}{\eta}-1\right)P_{out}$
Physics 9702 · AS & A Level · Energy conservation