Not nearly sufficient details for anything but guesses, but a loud whining noise which varies with engine speed has quite a few possible causes, but one of the more common (and expensive!) ones is a noisy transmission bearing.

It will usually get increasingly noisy to the point where you'll get it repaired long before it actually fails, but if it is a noisy bearing I suggest that you avoid any long/high speed journeys until it's sorted out.

But if you want an accurate diagnosis of the fault then take the car to an experienced home mechanic or a professional.

Next time you ask a similar question please state the car year, make, exact model and engine/transmission variant. It also helps to state the car mileage and whether it's been regularly maintained or not.

If it's an electric car or hybrid then that isn't really surprising. What is the question?

That's nice. Did you want to ask a question?

it is a regular automatic car