General Science — RRB NTPC General Awareness
General Science carries roughly 25% of General Awareness's 40 questions — the single heaviest topic across all three CBT 1 sections. It draws from basic physics, chemistry, and biology at a school-textbook level, rewarding broad and accurate recall over deep specialisation in any one branch.
1. What RRB NTPC actually asks
Expect direct factual recall questions spanning units and measurement, basic physics laws and phenomena, the periodic table and common chemical compounds, and human biology (body systems, nutrition, diseases). Nothing requires derivation or calculation — this is pure, broad recall.
2. Physics — units, measurement, and basic laws
| Quantity | SI Unit |
|---|---|
| Force | Newton (N) |
| Work / Energy | Joule (J) |
| Power | Watt (W) |
| Pressure | Pascal (Pa) |
| Frequency | Hertz (Hz) |
| Electric current | Ampere (A) |
| Temperature | Kelvin (K) |
Newton's three laws of motion: (1) An object stays at rest or in uniform motion unless acted on by an external force (inertia). (2) Force = mass × acceleration. (3) For every action, there is an equal and opposite reaction.
Speed of light in vacuum is approximately 3 × 10⁸ m/s — the fastest speed physically possible, per relativity.
3. Chemistry — elements, compounds, and everyday reactions
| Element | Atomic number | Common use/property |
|---|---|---|
| Hydrogen | 1 | Lightest element; used in rocket fuel |
| Carbon | 6 | Basis of all organic chemistry and life |
| Oxygen | 8 | Essential for respiration and combustion |
| Sodium | 11 | Reactive metal; found in table salt (NaCl) |
| Chlorine | 17 | Used in water purification |
pH scale runs from 0 to 14: below 7 is acidic, above 7 is basic (alkaline), and exactly 7 is neutral (pure water).
Common compounds: water (H₂O), table salt (NaCl), baking soda (NaHCO₃), carbon dioxide (CO₂).
4. Biology — human body and nutrition
An adult human body has 206 bones. Normal human body temperature is 37°C (98.6°F). The normal resting heart rate is roughly 60-100 beats per minute.
Vitamin deficiency diseases: Vitamin A deficiency causes night blindness; Vitamin C deficiency causes scurvy; Vitamin D deficiency causes rickets (in children) or osteomalacia (in adults); Vitamin B1 deficiency causes beriberi; Vitamin B3 deficiency causes pellagra.
Major body systems: the circulatory system (heart, blood vessels) transports blood; the respiratory system (lungs) handles gas exchange; the digestive system breaks down food; the nervous system (brain, spinal cord, nerves) coordinates body functions.
Worked examples
Q1. What is the SI unit of force?
Pick an option to check your answer.
Show explanation
Solution. The SI unit of force is the Newton (N), defined as the force needed to accelerate a 1 kg mass at 1 m/s². Joule measures energy/work, Watt measures power, and Pascal measures pressure — each a related but distinct physical quantity. Answer: (c).
Q2. Deficiency of which vitamin causes night blindness?
Pick an option to check your answer.
Show explanation
Solution. Vitamin A is essential for the light-sensing cells in the retina; its deficiency specifically impairs vision in low light, causing night blindness.
(a) Vitamin B1 deficiency causes beriberi, a nerve/cardiovascular condition, not a vision issue. (c) Vitamin C deficiency causes scurvy (connective tissue/gum disease). (d) Vitamin D deficiency causes rickets (bone disease), also unrelated to vision. Answer: (b).
6. Common traps
- Confusing SI units across quantities — Newton (force), Joule (energy), Watt (power), and Pascal (pressure) are frequently mixed up since they're all related to mechanics.
- Mismatching a vitamin with the wrong deficiency disease — each vitamin-disease pairing is specific and worth memorising as a fixed pair, not derived from general reasoning.
- Confusing atomic number with atomic mass — atomic number is the number of protons (defines the element); atomic mass includes neutrons too and varies by isotope.
- Assuming pH 7 is "neutral" means "harmless" in a chemical sense — neutral specifically refers to equal H⁺ and OH⁻ concentration, a precise chemical definition, not a general safety claim.
7. Guessing strategy
For unit-matching questions, eliminating options that are clearly units of a DIFFERENT category (e.g., a temperature unit when the question asks about force) often narrows the choice to two plausible options even without full certainty.
Summary
- General Science is roughly 25% of General Awareness's 40 CBT 1 questions — the single heaviest topic in the entire exam.
- Physics: know the SI units table cold, plus Newton's three laws of motion and the speed of light.
- Chemistry: know the atomic numbers of common elements, the pH scale, and common compound formulas.
- Biology: know the adult human bone count (206), normal body temperature/heart rate, and vitamin-deficiency disease pairings.
- This topic rewards broad, accurate recall across all three science branches, not depth in any single one.
- Vitamin-disease pairings and SI units are worth memorising as fixed, specific pairs rather than reasoned out from general principles.
