Q. 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? (UPSC Prelims 2013)
Answer: Gravity is the strongest of the four
Notes: Gravity is the weakest of the four fundamental forces, not the strongest. Electromagnetism acts on charged particles, weak nuclear force is responsible for certain types of radioactivity, and strong nuclear force binds protons and neutrons inside the atomic nucleus, making option 1 incorrect.