The phrase "magnetism of a" is technically grammatically correct, but it is not a complete sentence.
You could use it in a sentence as an attributive phrase, such as "The magnetism of a black hole is a powerful phenomenon."
Ferromagnetism — the simple magnetism of a bar magnet or compass needle — has been known for centuries.
The magnetism of a performance derived no longer from stylized behaviour but from intense personal revelation.
He feels real, somehow, with the magnetism of a rock star.
The firebursts and fly-pasts could not hope to match the magnetism of a match played on the ragged edge.
What remains a mystery is the magnetism of a person who carries himself as though he were holding an invisible porcupine under each armpit).
As a gawky Italian-American plumber who woos Saoirse Ronan's shy Irish shopgirl, Cohen does indeed carry himself with the slouchy magnetism of a 1950s method star.
Partly it was the sheer magnetism of an extraordinarily talented thinker.
An unidentified artist's 1830 painting of a girl in a red dress, at David A. Schorsch-Eileen M. Smiles, exudes the magnetism of an Alice Neel portrait.
Ramkhamhaeng's kingdom was built upon the personal power and magnetism of an exceptional ruler, and when the king died, his distant vassals soon broke away.
But back then the power of the oil cartels was stronger than the magnetism of an electric vehicle.
The two men do share something beyond the magnetism of celebrity: a suspicion that the nation is under threat from alien elements; a narrow definition of what it means to be an American; and an expressed belief that they speak the impolitic truth on behalf of those who are suppressed by political correctness.
