General Science and Technology
Core concepts
Physics: units, motion, force, energy, electricity basics. Chemistry: atomic structure, periodic table, acids–bases, and common reactions. Biology: cell structure, human body systems, nutrition, and disease vectors. Technology: basic electronics, renewable energy, and space/science milestones relevant to Bangladesh (e.g., Bangabandhu-1 satellite).
Traps to expect
- Unit conversions: 1 newton = 1 kg·m/s²; 1 joule = 1 N·m; 1 watt = 1 J/s. Mixing these is common.
- Acid–base indicators: litmus turns red in acid, blue in base; phenolphthalein is colorless in acid, pink in base.
- Blood circulation: arteries carry blood away from the heart (not always oxygenated - the pulmonary artery carries deoxygenated blood).
- Vector vs. scalar: speed is scalar, velocity is vector; mass is scalar, weight is vector.
- Vitamin deficiency pairs: vitamin C → scurvy; vitamin D → rickets; vitamin A → night blindness.
Rule of thumb
For any "which is NOT" science question, classify each option by category first (scalar/vector, acid/base, vitamin/disease). The odd one out is usually the answer, and classification prevents guessing.
Worked example
"A body of mass 2 kg accelerates at 3 m/s². What force acts on it?" Using F = ma: F = 2 × 3 = 6 newtons. Trap: if the question gave weight instead, multiply by g (9.8) - weight is a force, mass is not.