An electric motor must deliver $120\,\text{W}$ of mechanical output power. The motor has an efficiency of $80\%$. Which row is correct?
- Aelectrical power input $120\,\text{W}$, waste heat output $24\,\text{W}$
- Belectrical power input $120\,\text{W}$, waste heat output $96\,\text{W}$
- Celectrical power input $150\,\text{W}$, waste heat output $30\,\text{W}$
- Delectrical power input $150\,\text{W}$, waste heat output $120\,\text{W}$