General Science: notes & practice

Physics, chemistry and biology basics, the human body, everyday science, units and inventions — asked in SSC, RRB, NDA, CDS and most one-day exams.

Key topics

• Physics Basics

  Motion, force, work-energy, units (SI), light, sound, electricity; remember F = ma, P = W/t.

• Chemistry Basics

  Atoms, molecules, acids-bases-salts, common compounds and their formulas, metals and non-metals.

• Biology Basics

  Cell, tissues, photosynthesis, respiration, plant and animal classification.

• Human Body

  Systems (digestive, respiratory, circulatory, nervous), glands, vitamins, deficiency diseases.

• Everyday Science

  Why soap cleans, how pressure cookers work, dew, mirrors, magnets — one-line 'why' answers.

• Inventions & Units

  Scientists and their discoveries, SI units, prefixes and instrument names (barometer, hygrometer).

Practice questions

Our own practice questions in the style of past papers.

1. 1. The SI unit of force is:

   A. JouleB. NewtonC. PascalD. Watt

2. 2. Which gas is mainly responsible for the greenhouse effect on Earth?

   A. OxygenB. NitrogenC. Carbon dioxideD. Hydrogen

3. 3. Deficiency of iodine causes:

   A. RicketsB. GoitreC. AnaemiaD. Scurvy

4. 4. The powerhouse of the cell is the:

   A. NucleusB. RibosomeC. MitochondriaD. Golgi body

5. 5. Common salt is chemically:

   A. Sodium chlorideB. Calcium carbonateC. Sodium carbonateD. Potassium chloride

6. 6. A barometer measures:

   A. HumidityB. Atmospheric pressureC. Wind speedD. Temperature