99 Electricity And Magnetism Trivia Questions with Answers
99 public questions with answers, drawn from the well. How many can you answer?
At Bell Labs in 1947, what type of transistor was demonstrated by John Bardeen and Walter Brattain?
Answer
Point-contact transistor
What process generates most of Earth’s large-scale magnetic field?
Answer
The geodynamo
Which electrical law states that the algebraic sum of voltages around a closed loop is zero?
Answer
Kirchhoff’s voltage law
What instrument did Benjamin Franklin invent to protect buildings from lightning?
Answer
Lightning rod
Who patented a practical alternating-current transformer in the United States in 1886?
Answer
William Stanley Jr.
What is the name of the effect in which a changing magnetic field induces an electric field?
Answer
Electromagnetic induction
Which experiment first measured the electron’s charge-to-mass ratio?
Answer
J. J. Thomson’s cathode-ray experiment
Which scientist discovered radio waves experimentally in 1887?
Answer
Heinrich Hertz
Who built the first practical electric battery in 1800?
Answer
Alessandro Volta
Which law states that the current through a node equals the current entering it?
Answer
Kirchhoff’s current law
Which phenomenon explains why a compass needle points toward magnetic north?
Answer
Earth’s magnetic field
What type of wave is a radio signal in empty space?
Answer
Electromagnetic wave
Which scientist discovered the Hall effect in 1879?
Answer
Edwin Hall
Which scientist gives his name to the SI unit of capacitance, the farad?
Answer
Michael Faraday
What is the exact speed of light in a vacuum, a value central to electromagnetic theory?
Answer
299,792,458 metres per second
What was the first nuclear reactor to produce a self-sustaining chain reaction?
Answer
Chicago Pile-1
Who sent the first transatlantic radio signal in 1901?
Answer
Guglielmo Marconi
Who invented the Van de Graaff generator in 1929?
Answer
Robert J. Van de Graaff
What is the name of the region around a magnet where magnetic forces can be detected?
Answer
Magnetic field
Which particle carries electric current through a metal wire?
Answer
Electrons
What is the name of the three-phase electrical system used for most high-power transmission?
Answer
Three-phase power
What is the name of the current produced when a conductor moves through a magnetic field?
Answer
Induced current
Which scientist formulated the mathematical laws of electromagnetism now known as Maxwell's equations?
Answer
James Clerk Maxwell
What type of transformer increases alternating voltage while reducing current?
Answer
Step-up transformer
Which electromagnetic phenomenon makes a compass align with Earth’s magnetic field?
Answer
Magnetic torque
In electrostatics, what is the SI unit of electric dipole moment?
Answer
Coulomb-metre
Which physicist discovered the electron in 1897 through cathode-ray experiments?
Answer
J. J. Thomson
In electromagnetism, what is the SI unit of magnetic field strength H?
Answer
Ampere per metre
Which scientist discovered that a compass needle is deflected by an electric current in 1820?
Answer
Hans Christian Ørsted
What device uses a semiconductor junction to emit light when electric current passes through it?
Answer
Light-emitting diode
Which scientist demonstrated in 1752 that lightning is electrical using a kite experiment?
Answer
Benjamin Franklin