Low Jupyter CPU Usage

Question

I noticed that some cells take a long time to finish running on my Jupyter laptops. When I look in the task manager, I see that the python process uses only about 4% of the processor. I am using Python 3.6.2

I am on Windows, but I use the Bash on Ubuntu on Windows terminal to run the Jupyter laptop (maybe this helps). The processor is Core i7, and this process does not use all available RAM, therefore it is not a Swap memory problem.

Basically, why is it "throttled" so and how to fix it?