Why does combustion engines need multigeared transmission while electrical engines can make due with a single gear?

Question

So trying to figure out why electrical engine only needs a single gear while a combustion engines needs multiple gears. Cant wrap my head around it for some reason

EDIT: Thanks for all the explanation, but now another question popped up in my head. Would there ever be a point of having a manual electric car? I’ve heard rumors of Toyota registering a patent for a system which would mimic a manual transmission, but through all this conversation I assume there’s really no point?

In: 1567

Answer 1

Electric motors produce 100% torque from 0 RPM. Thats why we have diesel electric locomotives that can pull a tens of thousands of tons of train from standstill. The diesel engines power generators to create the electricity for the electric motors.

Diesel or gasoline engines deliver torque through a narrow RPM range so a gearbox is needed to utilize the right RPM range to maximize the corresponding torque.