What is the ratio of the efficiency for 75 watt to 750 watt motor?

To calculate or compare the efficiency ratio of a 75-watt motor to a 750-watt motor, we need specific data regarding the efficiency of each motor, which is not provided in your question. Efficiency in this context usually refers to how well the motor converts electrical energy into mechanical energy without waste (usually measured as a percentage). Without this specific information, calculating an exact ratio of efficiency between the two motors isn’t possible.

However, to give a generalized understanding, efficiency in electric motors can depend on various factors such as design, size, load, and operating conditions. Typically, larger motors (like a 750-watt motor compared to a 75-watt motor) can be more efficient than smaller ones because they have lower relative losses. For example, core losses and friction losses don’t scale linearly with motor size. This means a bigger motor might have proportionally lower losses compared to its output, making it more efficient. But this is a generalization and can vary based on the specific motors and their applications.

To accurately answer the question, specific efficiency values or a more detailed context for both motors would be necessary.