Question
Which one of the following statements is correct?
NDA
General Ability
General Science
2025
NDA 2025 (Phase 1)
NDA General Ability Question (2025) — Solution
Options
- A. A neutron is formed by combination of an electron and a proton. Therefore, it is neutral
- B. The mass of an electron is about 1/2000 times that of a proton
- C. An isotope of cobalt is used in the treatment of goiter
- D. J. J. Thomson proposed that the nucleus of an atom contains only neutrons
Answer
B. The mass of an electron is about 1/2000 times that of a proton
Step-by-step solution
Statement 1 is incorrect because a neutron is a fundamental subatomic particle, not a combination of an electron and a proton. Statement 2 is correct because the mass of an electron is approximately 1 1837 times the mass of a proton, which is roughly 1 2000 . Statement 3 is incorrect because an isotope of iodine (I-131) is used in the treatment of goiter, whereas an isotope of cobalt (Co-60) is used in the treatment of cancer. Statement 4 is incorrect because J. J. Thomson proposed the plum pudding model of the atom. The nucleus was discovered by Rutherford, and neutrons were discovered by James Chadwick. Answer: The mass of an electron is about 1/2000 times that of a proton
Related: General Ability — General Science · All PYQ Banks