General Science
What the domain tests
General Science tests school-level physics, chemistry and biology, with health, nutrition and environment applications. Questions reward definitions, units, body systems, diseases and simple numerical relations rather than advanced theory.
Core rules and concepts
- Physics: speed = distance/time; average speed uses total distance and total time; force, work, energy, SI units, reflection and electricity.
- Chemistry: acids and bases, pH, common salts, metals and non-metals, separation methods, symbols and valency.
- Biology: digestive, respiratory, circulatory and excretory systems; vitamins and deficiency diseases; pathogens and vectors; plant parts and photosynthesis.
- Environment: food chains, pollution, greenhouse gases and biodiversity.
Worked example
A body covers 10 m in 2 s and another 20 m in 3 s. Find average speed. Total distance = 10 + 20 = 30 m. Total time = 2 + 3 = 5 s. Average speed = 30/5 = 6 m/s. Do not average 5 m/s and 6.67 m/s; that gives the wrong result because the times differ.
Traps that cost marks
- Confusing mass with weight; weight changes with gravity, mass does not.
- Treating average speed as the mean of two speeds.
- Mixing virus and bacteria; antibiotics do not cure viral infections.
- Forgetting that pH below 7 is acidic and above 7 is basic.
- Using the wrong SI unit, such as joule for power instead of watt.
Exam habit
Revise diagrams and deficiency-disease tables, then practise one-line numericals.