PencilGo

Grade 11 · Science · Physics

11th grade The electromagnetic spectrum and its uses worksheet

6 printable versionsChallenge Me10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

When it’s done, scan the sheet with your phone and PencilGo marks it and picks the next one. Create a free account

Version
Print

The electromagnetic spectrum and its uses

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. A radar pulse goes from Earth to the Moon, 384400 km away, and back. How long does the trip take, Ari?

  2. A probe at the Sun–Earth L1 point is 1500000 km away. Bo sends a command and gets the reply. How long is the round trip?

  3. A satellite hovers 35786 km up. Esme sends a question up and down to a friend, and the reply goes up and down. How long is the delay?

  4. Read this first

    Five bands (example data)

    bandfrequency
    Radio100 MHz
    microwave10 GHz
    infrared30 THz
    visible500 THz
    ultraviolet1000 THz

  5. Using the band table, how many times more energy does a visible photon carry than a microwave photon, Jun?

    • About 50 times, treating THz and GHz alike
    • About 1 ÷ 50,000, since microwaves carry more
    • About 50,000 times less, since visible has the shorter wavelength
    • About 50,000 times, since E = hf

  6. A 5G phone gets strong 28 GHz signals outdoors but weak ones indoors; lower-frequency signals reach indoors better. Which explains this, Kira?

    • Higher-frequency waves travel slower, so they arrive late
    • Walls absorb low frequencies more than high ones
    • Shorter 28 GHz waves are blocked more by walls
    • Higher-frequency photons carry less energy, so they stop

  7. Luz builds a half-wave antenna for a 98.1 MHz FM station. About how long should it be?

    • About 1.5 m
    • About 15 cm, a tenth of a wavelength
    • About 0.76 m, a quarter wavelength
    • About 3.1 m, one whole wavelength

  8. Noah says the sky is blue because the air absorbs blue light. Air scatters light roughly as 1/λ⁴. Judge the claim.

    • Not supported: air scatters red light more than it scatters blue
    • Not supported: air scatters blue about 4 times more than red
    • Supported: the blue light we see is what the air lets through
    • Supported: scattering and absorbing are one and the same process

  9. Pia wants to test whether a wall weakens a Wi-Fi signal. Which design is best?

    • Measure at the same distance with and without the wall, several times each
    • Measure the router's label power and compare it with the wall's thickness
    • Measure with the wall in place, then again much farther from the router
    • Measure once in each room, wherever the signal is easiest to reach

  10. Why do X-ray telescopes orbit above the atmosphere, while many radio telescopes work on the ground, Ren?

    • X-rays are too bright to be measured from the ground
    • Air absorbs X-rays but passes many radio waves
    • Radio waves travel faster, so they reach the ground
    • Radio waves carry more energy, so they pass through air

  11. Zee tunes a radio telescope to the 1,420 MHz hydrogen line. What wavelength is that, and why can radio cross dust that blocks light?

    • About 21 m; dust grains are far smaller than that wavelength
    • About 2.1 cm; dust grains are larger than the wavelength
    • About 21 cm; radio waves carry more energy, so they push through
    • About 21 cm; dust grains are far smaller than that wavelength
PencilGopencilgo.com

11th grade The electromagnetic spectrum and its uses worksheet – printable
Print: 123456

About this worksheet

The electromagnetic spectrum and its uses. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can order the spectrum by frequency, wavelength and photon energy, and find wavelengths from λ = c ÷ f with kHz, MHz and GHz.
  • I can find photon energy from E = hc ÷ λ (hc ≈ 1,240 eV·nm) and compare bands by E = hf.
  • I can explain uses with wave ideas: why mesh blocks microwaves but not light, why long waves diffract round buildings, why shorter waves resolve finer detail, why skin glows in infrared (Wien's law), and why telescopes go to orbit.
  • I can find signal times (Moon, L1, geostationary satellite) counting every leg, and judge claims such as "microwaves cook from the inside" or "the air absorbs blue light".

Standard: supports HS-PS4-5

Words to know

frequency f, wavelength λ: Waves per second; length of one wave, with c = fλ

photon: One packet of light, with energy E = hf

electronvolt (eV): A small unit of energy used for photons

diffraction: Waves bending around an obstacle or through a gap

Wien's law: A warm object's glow peaks at λ = 2.898 × 10⁻³ m·K ÷ T

Common mistakes

Your child used the frequency number without its prefix. MHz, GHz and kHz must become hertz before dividing into c.

Your child divided the wrong way round. The wavelength is c ÷ f, and the energy is hc ÷ λ.

Your child multiplied by hc. Energy goes down as wavelength goes up, so divide hc by λ.

Questions parents ask

What is the most common mistake with the electromagnetic spectrum and its uses?

Your child used the frequency number without its prefix. MHz, GHz and kHz must become hertz before dividing into c.

Are these 11th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

More physics

See all Physics

Every sheet you scan goes into your child’s record: dated, marked and ready for the year-end portfolio. Homeschool records

Ready for easier practice?

Print a sheet, scan it when it’s done, and PencilGo picks the next one.

Create a free account