Electromagnetic Attraction Trivia Quiz

Answer: James Maxwell

Maxwell's equations in the 19th century laid the foundation for the amazing discoveries and advancements that would follow in the 20th century. In a poll conducted in 1999, the top 100 physicists of the day voted on the greatest physicists of all time. Albert Einstein topped the list, with Isaac Newton placing second, and James Maxwell in the third spot (Niels Bohr was fourth).

Yet, when Einstein was lauded as having achieved his great accomplishments on Newton's shoulders, he disagreed, saying "No I don't. I stand on the shoulders of Maxwell."

Maxwell's equations were important in unifying the various different, and previously described phenomena of electricity, magnetism, and light into one connected spectrum, demonstrating how fluctuating electric and magnetic fields propagate at a constant speed in a vacuum. His theories and equations also led him to predict the existence of radio waves.

Answer: Heinrich Hertz

The hertz (Hz) was chosen in 1930 to represent the number of cycles per second (cps) frequency by the International Electrotechnical Commission, and in 1960 it officially replaced cps as the standard term by the CGPM (Conférence générale des poids et mesures).

It was Heinrich Hertz who took Maxwell's theory and proved it correct by producing radio waves for the first time in 1887 (20 years later). For this and his other work, his name lives on in everyday use.

Answer: Medium Frequency (MF) - 300 to 3,000 kHz

The International Telecommunication Union (ITU) is an agency of the United Nations that regulates and facilitates the use of the radio spectrum around the globe. To this end, twelve bands were defined, with each separated by a power of ten.

Our standard broadcasting AM radio falls within the Medium Frequency band, while FM radio falls within the Very High Frequency band. Satellite radio is broadcast in the Super High Frequency band.

The lowest end of the spectrum, with a frequency (and wavelength) of 3 to 30 Hz (100,000 to 10,000 km) is called the Extremely Low Frequency (ELF) band. Continuing from there:

Super Low Frequency (SLF) - 30 to 300 Hz (10,000 to 1,000 km)
Ultra Low Frequency (ULF) - 300 to 3,000 Hz (1,000 to 100 km)
Very Low Frequency (VLF) - 3 to 30 kHz (100 to 10 km)
Low Frequency (LF) - 30 to 300 kHz (10 to 1 km)
Medium Frequency (MF) - 300 to 3,000 kHz (1 km to 100 m)
High Frequency (HF) - 3 to 30 MHz (100 to 10 m)
Very High Frequency (VHF) - 30 to 300 MHz (10 to 1 m)
Ultra High Frequency (UHF) - 300 to 3,000 MHz (1 m to 10 cm)
Super High Frequency (SHF) - 3 to 30 GHz (10 to 1 cm)
Extremely High Frequency (EHF) - 30 to 300 GHz (1 cm to 1 mm)
Tremendously High Frequency (THF) - 300 to 3,000 GHz (1 to 0.1 mm)

Answer: High Fidelity

When originally introduced, the Wi-Fi Alliance (established in 1998) advertised Wi-Fi as "The Standard for Wireless Fidelity", using the relatability of the well-known term 'Hi-Fi' (for 'High Fidelity') from the music industry. The term 'wireless fidelity,' was never officially recognized as the meaning of Wi-Fi (there is conflicting information on this subject).

The original IEEE 802.11 wireless networking standard was established at the 2.4 GHz wavelength, but has since expanded to include 900 MHz, 3.6 GHz, 4.9 GHz, 5 GHz, 5.9 GHz and 60 GHz bands. Wi-Fi devices communicate by sending blocks of data (called 'data packets') over the established radio bands through the modulating and demodulation of carrier waves (hence the term 'modem').

Answer: Dielectric heating

N.B. - microwaves are simply 'short' electromagnetic wavelengths, and fall within the upper end of the radio spectrum in the 1 to 1000 GHz range.

Polar molecules are those that have a negatively charged end and a positively charged end. When microwaves are projected through a material (like food) with polar molecules (like water), this causes the molecules to constantly realign themselves with the microwaves. When you add in the reflective material within a microwave oven, this means a lot of molecular movement, which then transfers to neighbouring (non-polar) molecules, moving (and warming) them as well.

This also explains why some parts of your meal tend to be warmer than other parts as you use your microwave oven - it is a process to warm the whole.

Answer: Infrared

*Most* TV remote controls use the infrared spectrum (between 300 GHz and 430 THz), which is not quite in the visual spectrum, although there are some animals that can see infrared. At the low power level of most remotes, your device will send infrared signals up to a range of about 10 to 20 meters, and they are unable to penetrate walls, generally requiring line-of-sight to work effectively.

The infrared pulses approximate binary code to enable your receiving device (TV, DVD player, etc) to interpret your signal to perform the different functions you require, like changing channels or manipulating the volume.

Answer: Newton

After experimenting with prisms and white light in the late 17th century, Sir Isaac Newton published "Opticks: or a Treatise of the Reflexions, Refractions, Inflexions and Colours of Light". His original division of colours only included red, orange, yellow, green, blue, and violet, but indigo was added later to make a 'perfect' seven, and to include a correlation to the notes of the musical scale.

As our understanding of the visual spectrum has advanced over the centuries, the colour names have not always been the same. Where Newton named 'blue' is often today referred to as 'cyan', and his 'indigo' is today's 'blue'.

The visible spectrum frequencies (and wavelengths) are as follows:

Red - 400 to 480 THz (625 to 700 nm)
Orange - 480 to 510 THz (590 to 625 nm)
Yellow - 510 to 530 THz (565 to 590 nm)
Green - 530 to 600 THz (500 to 565 nm)
Blue/Cyan - 600 to 620 THz (485 to 500 nm)
Indigo/Blue - 620 to 670 THz (450 to 485 nm)
Violet - 670 to 790 THz (380 to 450 nm)

Answer: 10%

When radiation from our sun reaches the top of the earth's atmosphere, it is comprised of approximately 50% infrared light, 40% visible light, and just 10% ultraviolet light. Our atmosphere manages to absorb about 77% of that 10%, leaving only 3% to reach the planet's surface.

The entire range of the ultraviolet spectrum extends from 800 THz to 30,000 THz, although when measuring UV, it is generally referred to by wavelength rather than by frequency. At the lower end (just above the visible spectrum), UV-A radiation has a wavelength between 315 to 400 nm, with UV-B between 280 to 315 nm.

(Pictured - a tanning bed, which utilizes UV radiation)

Answer: False

Wilhelm Röntgen (1845-1923) discovered x-rays in 1896 and went on to live to the age of 58, when he died from colorectal cancer. He understood the importance of the medical applications of x-rays immediately, sharing news of his discovery throughout the medical and scientific community. The dangers of experimentation with x-rays and their applied use were quickly discovered (as soon as 1896), but overall, the value of x-rays as a diagnostic tool outweighed (and still outweigh) the risks. Over time, a better understanding of the danger and how to mitigate it (shielding, as an example) have made the use of x-rays a ubiquitous practice.

X-rays, or Röntgen rays, fall within the 30 PHz to 30 EHz frequency range (10 pm (picometers) to 10 nm wavelength).

Answer: Radioactive nuclei

Both x-rays and gamma rays are ionizing radiation, but gamma rays are much more dangerously penetrative, with such a short wavelength that shielding against it is comparatively very difficult (it can pass between atoms). Where x-rays are produced through accelerating electrons to strike against a target material (like tungsten), gamma rays are produced through the radioactive decay of atomic nuclei, (like with radiation-emitting radium or uranium, or in nuclear chain reactions).

Gamma radiation was discovered by Ernest Rutherford in 1900 while studying radium's radioactivity.

Gamma rays are defined as having a frequency greater than 10 EHz, or a wavelength shorter than 10 pm.