She computed for George Campbell, who applied mathematical methods to the problems of long-distance electrical transmissions.

[1] Her thesis at MIT was supervised by Arthur E. Kennelly and was titled "Behavior of a lumpy artificial transmission line as the frequency is indefinitely increased.

The device could solve line equations involving hyperbolic functions ten times faster than previous methods.

On February 8, 1926, as the first woman to deliver a paper at the American Institute of Electrical Engineers' (AIEE) annual meeting, she showed the use of hyperbolic functions for calculating the maximum power that a line could carry without instability.

This two-volume textbook teaches about her adaption of the symmetrical components system, in which she became interested while working for the second time at GE.

Clarke adopted this system to the three-phase components that are the basis of the electrical grid in the United States.

[2] She was the first woman to be accepted as a full voting member in the American Institute of Electrical Engineers.

[17] In 1954, she received the Society of Women Engineers (SWE) Achievement Award,[18] which was presented to her by Evelyn Jetter, one of SWE's founders[19] and inventor of the automotive ignition transistor, "in recognition of her many original contributions to stability theory and circuit analysis.