Can i use an iMac as an external display with my windows Lenovo yoga 11e?

No, you cannot use an iMac as an external display for your Windows Lenovo Yoga 11e directly. iMacs do have a Target Display Mode, but this feature is only compatible with certain older iMac models and typically only works with other Apple devices. Additionally, Windows laptops do not support the necessary protocols to connect to an iMac in this manner. You might consider using third-party software solutions for screen sharing, but this won't provide the same experience as a direct connection.