Physics

Electromagnetic Waves and Spectrum

659 Questions

Electromagnetic waves and spectrum questions test a candidate's understanding of radiation frequencies, wavelengths, and the properties of different rays like infrared, ultraviolet, and visible light. Concepts also cover practical applications in astronomy and the fundamental speed of light calculations. This physics topic appears regularly in general science sections of major competitive examinations.

UV rays propertiesElectromagnetic radiation frequencyWavelength identificationSpeed of light calculationsBlack body radiation

Electromagnetic Waves and Spectrum Questions

Multiple choice

What is the name of the region of the electromagnetic spectrum with wavelengths between 1 and 10 meters?

  1. VHF radio waves

  2. UHF radio waves

  3. Microwave radio waves

  4. HF radio waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

VHF radio waves have wavelengths between 1 and 10 meters.

Multiple choice

Which type of electromagnetic radiation is used in radar systems?

  1. X-rays

  2. Gamma rays

  3. Microwaves

  4. Infrared waves
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Microwaves are used in radar systems because they can be reflected by objects.

Multiple choice

What is the name of the region of the electromagnetic spectrum with wavelengths between 10 and 100 meters?

  1. HF radio waves

  2. MF radio waves

  3. LF radio waves

  4. VLF radio waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

HF radio waves have wavelengths between 10 and 100 meters.

Multiple choice

What is the name of the region of the electromagnetic spectrum with wavelengths between 100 and 1000 meters?

  1. LF radio waves

  2. MF radio waves

  3. VLF radio waves

  4. ULF radio waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

LF radio waves have wavelengths between 100 and 1000 meters.

Multiple choice

What is the name of the region of the electromagnetic spectrum with wavelengths between 1000 and 10000 meters?

  1. VLF radio waves

  2. ULF radio waves

  3. SLF radio waves

  4. ELF radio waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

VLF radio waves have wavelengths between 1000 and 10000 meters.

Multiple choice

Which type of electromagnetic radiation is used in submarine communication?

  1. Infrared waves

  2. Ultraviolet waves

  3. X-rays

  4. VLF radio waves
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

VLF radio waves are used in submarine communication because they can travel long distances and penetrate water.

Multiple choice

What is the name of the region of the electromagnetic spectrum with wavelengths longer than 10000 meters?

  1. ELF radio waves

  2. SLF radio waves

  3. ULF radio waves

  4. VLF radio waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ELF radio waves have wavelengths longer than 10000 meters.

Multiple choice

Which of the following is not a type of electromagnetic radiation?

  1. Visible light

  2. Infrared radiation

  3. Ultraviolet radiation

  4. Radio waves
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Radio waves are a type of mechanical wave, not electromagnetic radiation.

Multiple choice

What is the basic unit of light in quantum optics?

  1. Photon

  2. Electron

  3. Neutron

  4. Proton
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In quantum optics, the basic unit of light is the photon, which is a quantized packet of electromagnetic energy.

Multiple choice

The spectral resolution of an image is determined by:

  1. The number of different wavelengths of electromagnetic radiation used to acquire the image

  2. The width of the spectral bands used to acquire the image

  3. The sensitivity of the sensor to different wavelengths of electromagnetic radiation

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The spectral resolution of an image is determined by the number of different wavelengths of electromagnetic radiation used to acquire the image, the width of the spectral bands used to acquire the image, and the sensitivity of the sensor to different wavelengths of electromagnetic radiation.

Multiple choice

What is the Hubble Space Telescope's sensitivity?

  1. 10^-12 watts per square meter

  2. 10^-14 watts per square meter

  3. 10^-16 watts per square meter

  4. 10^-18 watts per square meter
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Hubble Space Telescope's sensitivity is 10^-18 watts per square meter, which is about the brightness of a single candle seen from a distance of 100 kilometers.

Multiple choice

What is the Hubble Space Telescope's wavelength range?

  1. Ultraviolet to near-infrared

  2. Visible light to near-infrared

  3. Infrared to submillimeter

  4. Radio waves to microwaves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Hubble Space Telescope's wavelength range is ultraviolet to near-infrared, which means that it can see light with wavelengths from 115 nanometers to 2.5 micrometers.

Multiple choice

What is the primary radiation detected by gamma-ray telescopes?

  1. Visible light

  2. Infrared radiation

  3. Gamma rays

  4. Radio waves
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Gamma-ray telescopes are specialized instruments designed to detect and study gamma rays, which are the most energetic form of electromagnetic radiation.

Multiple choice

What is the electromagnetic spectrum?

  1. The range of wavelengths of electromagnetic radiation.

  2. The range of frequencies of electromagnetic radiation.

  3. The range of energies of electromagnetic radiation.

  4. The range of intensities of electromagnetic radiation.

  5. The range of polarizations of electromagnetic radiation.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The electromagnetic spectrum is the range of wavelengths of electromagnetic radiation.

Multiple choice

Which of the following is not a type of electromagnetic radiation?

  1. Gamma rays

  2. X-rays

  3. Ultraviolet rays

  4. Infrared rays

  5. Radio waves
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Radio waves are not a type of electromagnetic radiation, but rather a type of mechanical wave.