Motor Efficiency: Increase in Voltage & Why?

[heena1988]

for my A level coursework i am doing the efficieny of a motor, I've just about sussed the theory . Now i have found out that the efficieny increases as the voltage increases and its wrong! i need help on saying why this would be the case. help would be much appreciated!

 

[berkeman]

Welcome to the PF, heena1988. Homework and coursework questions need to be posted here in the Homework Help forums (where I've moved your thread). And you need to show us some of your own work and thoughts in order for us to help you.

So, what factors go into the efficiency of an electric motor? There are many different types of electric motor -- which type(s) are you asked about? What are the loss mechanisms in motors (there are several) that keep the motor from being 100% efficient in converting electrical energy to mechanical energy?