2013 · Science & TechnologyPrevious Year Question
Q45.
The known forces of nature can be divided into four classes, viz., gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct?
A. Gravity is the strongest of the four
B. Electromagnetism acts only on particles with an electric charge
C. Weak nuclear force causes radioactivity
D. Strong nuclear force holds protons and neutrons inside the nucleus of an atom
Answer

A

Explanation

Gravity is actually the weakest of the four forces — it is about 10^-36 times the strength of the strong nuclear force. This weakness is easily demonstrable in everyday life when static electricity can lift paper against gravity.