SCIENCE 10 Q2 REVIEWER

In a hospital, X-rays are used to scan bones, and gamma rays treat tumors. How do their wavelengths compare?

• X-rays have longer wavelengths than gamma rays.

• X-rays and gamma rays have the same wavelength.

Answer explanation

X-rays have longer wavelengths than gamma rays. This is a fundamental property of electromagnetic radiation, where gamma rays are more energetic and thus have shorter wavelengths compared to X-rays.

A weather radar uses microwaves, while a TV remote uses infrared. Arrange these waves from longest to shortest wavelength:

• Infrared → Visible Light → Microwaves

• Microwaves → Infrared → Visible Light

Answer explanation

Microwaves have longer wavelengths than infrared, which in turn is longer than visible light. Therefore, the correct order from longest to shortest wavelength is Microwaves → Infrared → Visible Light.

Fiber optic cables use visible light, and Wi-Fi routers use microwaves. Which of the following statements is true about these two EM waves?

• Microwaves have longer wavelengths than visible light.

• Visible light has longer wavelengths than microwaves.

Answer explanation

Microwaves have longer wavelengths than visible light. The electromagnetic spectrum shows that visible light falls between ultraviolet and infrared, while microwaves are positioned at longer wavelengths than visible light.

A proposed Martian rover uses subsurface imaging to search for ice layers. Which EM wave’s wavelength-to-penetration depth ratio would best resolve meter-deep ice without damaging structures?

• Infrared (long λ, absorbed by regolith)

• Terahertz waves (mid-range λ, moderate penetration, non-ionizing)

Answer explanation

Terahertz waves have a mid-range wavelength and moderate penetration depth, making them ideal for resolving meter-deep ice layers without damaging structures, unlike gamma rays or X-rays which are ionizing or scattered.

A radio tower emits radio waves, and a microwave oven uses microwaves. Which has the shorter wavelength?

• Radio Waves

• Microwaves

Answer explanation

Microwaves have a shorter wavelength than radio waves. This is because microwaves are part of the electromagnetic spectrum with higher frequencies, resulting in shorter wavelengths compared to radio waves.

Astronomers use infrared telescopes to study stars and radio telescopes for galaxy mapping. Which of the following lists orders these waves correctly from longest to shortest wavelength?

• A. Radio → Infrared → X-rays

• C. Infrared → Microwaves → Radio

Answer explanation

The correct order from longest to shortest wavelength is Radio → Infrared → X-rays. Radio waves have the longest wavelengths, followed by infrared, and then X-rays, which have much shorter wavelengths.

A thermal camera detects infrared waves, and a UV lamp sterilizes surfaces. Which has the longer wavelength?

• Infrared

• Ultraviolet

Answer explanation

Infrared waves have longer wavelengths than ultraviolet waves. This makes infrared the correct answer, as it falls within the range of wavelengths that are longer than those of UV light.

Which sequence correctly orders EM waves from shortest to longest wavelength?

• X-rays → Visible Light → Infrared → Radio

• Gamma → X-rays → Radio → Microwaves

Answer explanation

The correct order of EM waves from shortest to longest wavelength is X-rays → Visible Light → Infrared → Radio. This sequence accurately reflects the increasing wavelength and decreasing frequency of electromagnetic radiation.

A satellite uses radio waves for communication, while a laser pointer uses visible light. How do their wavelengths compare?

• Radio waves are shorter than visible light.

• Visible light is shorter than radio waves.

Answer explanation

Radio waves have longer wavelengths than visible light. This means that the wavelength of visible light is shorter than that of radio waves, making the correct choice 'Visible light is shorter than radio waves.'

Which pair of EM waves has wavelengths between those of ultraviolet and radio waves?

• Infrared and microwaves

• Microwaves and gamma rays

Answer explanation

Infrared and microwaves have wavelengths that fall between ultraviolet and radio waves on the electromagnetic spectrum, making them the correct choice. X-rays and gamma rays have shorter wavelengths, while visible light is also shorter.