Electromagnetic radiation is more common than you think. Radio andTV stations emit radio waves when they broadcast their programs;microwaves cook your food in a microwave oven; dentists use X raysto check your teeth. Even though they have different names anddifferent applications, these types of radiation are really all thesame thing: electromagnetic (EM) waves, that is, energy thattravels in the form of oscillating electric and magnetic fields

Consider the following:
radio waves emitted by a weather radar system to detectraindrops and ice crystals in the atmosphere to study weatherpatterns;
microwaves used in communication satellite transmissions;
infrared waves that are perceived as heat when you turn on aburner on an electric stove;
the multicolor light in a rainbow;
the ultraviolet solar radiation that reaches the surface of theearth and causes unprotected skin to burn; and
X rays used in medicine for diagnostic imaging

Electromagnetic waves (EM waves) refer to waves carrying electromagnetic radiant energy which are propagated through vacuum or non-vacuum (material medium). They range from radio waves to gamma rays; they travel through space at the speed of light (about 300 million metres per second) and they are measured in photons.

The EM waves have the following characteristics:

1. They have different wavelengths

2. They have different frequencies

3. They travel at the speed of light independent of the medium of propagation (vacuum or material medium)

4. They do not require a media to be propagated

Based on the explanation above, Options a (They have different wavelengths) and b (They have different frequencies) are the correct answers