Behind the Units: Electromagnetism Quiz

Answer: volt

Count Alessandro Volta (1745 - 1827), an Italian, also studied electricity in the atmosphere and isolated methane gas. His most important contribution, however, was his follow-up on the experiments of his friend Luigi Galvani, who had observed that an electrical current was produced when two different metals were placed in the tissue of a dead frog. Galvani attributed this to 'animal electricity,' but Volta realized that it was really the metals which created the current.

Answer: ampere

Andre Marie Ampere (1775-1836), a Frenchman, also showed that wires carrying current in the same direction were attracted. The laws he formulated, which deal with the interaction between currents and their associated magnetic fields, are crucial to modern electromagnetism.

He also invented the astatic needle, which neutralizes the Earth's magnetic field and thus makes galvanometers possible.

Answer: ohm

Georg Simon Ohm (1789 - 1854), a German, was known for the meticulousness of his experiments. Although he was poorly funded and had to make his own electrical wires, his results were exceptionally accurate. I = V divided by R, now known as Ohm's Law, is the most basic equation used to describe electrical circuits.

Answer: coulomb

Charles Augustin de Coulomb (1736 - 1806), a Frenchman, also published an important analysis of the friction in machinery, and helped Napoleon's government devise the metric system. The torsion balance is basically a rod hung on a thin wire, with some object (in his experiments, a charged one) attached to one end.

Another object is brought close to that end of the rod, and if there is a force between them, the rod will begin to turn in response to it. When the whole thing stops moving, it's in equilibrium: the force between the objects is exactly balanced by the force exerted by the twisted wire. Measure the twist in the wire, and you have the force between the objects!

Answer: oersted

Hans Christian Oersted (1777 - 1851), a Dane, placed a compass near a current-carrying wire in 1820. He and his physics class observed that the compass needle was deflected when the wire was brought close by, thus showing conclusively that electricity and magnetism were related and opening a whole new field of study.

As for cgs units, they're a modification of SI units and were once common in electromagnetism classes, though SI units are more widely useful.

Answer: gauss

Karl Friedrich Gauss (1777 - 1855), a German, was a child prodigy in addition to his adult works of genius. He's best known for his work in geometry (he constructed a regular 17-sided polygon with a straightedge and a compass, a task which had failed the ancient Greeks) and especially for his contributions to algebra (he proved the fundamental theorem thereof) and to number theory, a field which he largely founded.

Answer: tesla

Nikola Tesla (1856 - 1943), a Serbian-born American, sold the patent for his alternating-current system (which included motors, transformers and dynamos) to George Westinghouse, who used the technology to prevail over Edison's direct-current strategy for providing electricity.

He also discovered terrestrial stationary waves, and his induction devise - the Tesla coil - helped make radio and television broadcasting possible.

Answer: farad

Michael Faraday (1791 - 1867), an Englishman, was an elder in the Sandemanian Christian Church in addition to his scientific achievements. He also discovered electromagnetic rotations, the magneto-optical effect (the bending of light by strong magnets), diamagnetism (a class of non-iron substances with strong magnetic properties, such as liquid oxygen), and field theory.

His contributions to physics cannot be overstated.

Answer: weber

Wilhelm Eduard Weber (1804 - 1891), a German and a friend of Gauss (Question 6), devoted his life to studying the electrical structure of matter as well as electrodynamics. He was also active in astronomy at the observatory in Gottingen.

Answer: henry

Joseph Henry (1797 - 1878), an American, also helped Samuel Morse develop the telegraph. Inductance measures the ability of an electric current to create a magnetic field surrounding it, and vice {versa;} an object with the property of self-induction, called an inductor, is one of the basic circuit elements in modern electronics.