Category 1: Wave Basics
What type of wave requires a medium to travel?
Mechanical wave
What is the distance between two consecutive crests or troughs called?
Wavelength
Which electromagnetic wave has the longest wavelength?
Radio waves
Which EM wave is commonly used for radio and television broadcasting?
Radio waves
Which EM wave helps the body produce vitamin D?
Ultraviolet
What type of wave is formed through the interaction of electric and magnetic fields?
Electromagnetic wave
What is the number of complete wave cycles passing a point each second called?
Frequency
Which part of the EM spectrum can be detected by the human eye?
Visible light
Which EM wave is commonly used in remote controls and thermal cameras?
Infrared
Which EM wave can damage skin tissue when a person receives too much exposure from sunlight?
Ultraviolet
In a transverse wave, how do particles move compared with the direction the wave travels?
Perpendicular to the direction of wave travel
If wavelength becomes shorter, what happens to frequency?
Frequency increases
Which EM wave lies between radio waves and infrared radiation in the spectrum?
Microwaves
What device inside a microwave oven produces microwave radiation?
Magnetron
Why should unnecessary exposure to X-rays be limited?
High-energy X-rays can damage cells and tissues
What wave behavior occurs when a wave bends as it enters a different medium?
Refraction
Electromagnetic waves travel at approximately what speed in a vacuum?
3 × 10⁸ m/s
Which type of EM radiation has greater energy and can penetrate more deeply than X-rays?
Gamma rays
A doctor wants to examine a patient's broken bone. Which electromagnetic wave should be used?
X-rays
Gamma rays can be harmful, but what important medical use of gamma rays is described in the lesson?
Cancer therapy
Two waves meet and combine in the same medium. What wave property is being demonstrated?
Interference
A wave has a short wavelength and very high frequency. Compared with a wave of longer wavelength, how would its energy generally differ?
It has greater/higher energy
Arrange these from lowest to highest energy: visible light, gamma rays, radio waves, X-rays.
Radio waves → Visible light → X-rays → Gamma rays
A security system must detect a person's body heat even in darkness. Which EM wave is most appropriate, and why?
Infrared, because warm bodies emit infrared radiation/body heat
A learner says, “The most useful EM waves are also always the safest.” Explain why this statement is incorrect using one example from the lesson.
Answers may vary; e.g., X-rays are useful for medical imaging but excessive exposure can damage cells and tissues, or gamma rays can treat cancer but excessive exposure can cause serious tissue damage