[amp_mcq option1=”Light waves on it” option2=”Microwaves on it” option3=”Radio waves on it” option4=”Ultra high frequency waves on it” correct=”option3″]
The correct answer is: C. Radio waves on it.
Police officers use radar guns to measure the speed of approaching cars. Radar guns emit radio waves that bounce off the car and return to the gun. The gun calculates the speed of the car based on the time it takes for the waves to travel to the car and back.
Light waves, microwaves, and ultra high frequency waves are all types of electromagnetic radiation. Electromagnetic radiation is a form of energy that travels in waves. The waves can have different wavelengths, and the wavelength determines the type of radiation.
Light waves have the shortest wavelength of all types of electromagnetic radiation. Microwaves have a longer wavelength than light waves, and ultra high frequency waves have a longer wavelength than microwaves.
Radio waves have the longest wavelength of all types of electromagnetic radiation. This is why radio waves are used to transmit signals over long distances.
Radar guns use radio waves because radio waves can penetrate through fog and rain. This makes it possible for police officers to measure the speed of cars even in bad weather conditions.
Light waves, microwaves, and ultra high frequency waves cannot penetrate through fog and rain. This is why they are not used by police officers to measure the speed of cars.