Which one of the following pairs of rays is electromagnetic in nature?
X-rays and gamma rays pairs of rays is electromagnetic in nature.
Electromagnetic (EM) radiation is a form of energy that is all around us and takes many forms, such as radio waves, microwaves, X-rays and gamma rays. Sunlight is also a form of EM energy, but visible light is only a small portion of the EM spectrum, which contains a broad range of electromagnetic wavelengths.
When you get yourself a radiography done, that machine doctors use emits gamma rays (also known as x-rays). Any radioactive element (such as radium, uranium and thorium) will emit gamma rays until their energy runs out. Gamma rays are also used as a cancer cure, since they can kill living cells.