Final answer:
In automotive applications, electro-magnetism powers electric motors which start cars and propel electric and hybrid vehicles by converting electrical energy to mechanical work through magnetic force. The principle of electro-magnetism is also essential in other technological and medical applications.
Step-by-step explanation:
Electro-magnetism is widely utilized in automotive applications, primarily in the function of electric motors. These motors have loops of wire that are exposed to a magnetic field. When electric current passes through these loops, a magnetic force produces torque, which in turn rotates a shaft and converts electrical energy into mechanical work. This principle is behind various uses including starting cars, operating vehicle amenities, propelling electric and hybrid vehicles, and much more.
Apart from automotive uses, electro-magnetism is key in generators for producing electricity, in medical equipment such as MRI machines, in data storage devices like hard drives, and in public security systems such as airport gates. The transformative power of magnetism and its ability to induce electric currents is vital to today's technological society.