Geography
Core concepts
Physical geography (landforms, rivers, climate, erosion), Bangladesh geography (rivers, deltas, districts, Sundarbans), and world geography (continents, oceans, major mountain ranges, straits, and climate zones). Know map basics: latitude, longitude, GMT offsets, and the Tropic of Cancer's path through Bangladesh.
Traps to expect
- River source/delta confusion: the Padma, Meghna, and Jamuna form the world's largest delta; the Brahmaputra is called Jamuna inside Bangladesh.
- Longitude and time: every 15° of longitude equals one hour; Bangladesh Standard Time is UTC+6.
- Tropic of Cancer passes through India and near Bangladesh's northern districts - questions often place it wrongly through the center.
- Largest vs. longest: the Amazon carries the most water; the Nile is often cited as longest.
- Sundarbans: it is a tidal halophytic mangrove forest, not a rainforest.
Rule of thumb
For time-zone problems: longitude difference ÷ 15 = hour difference; add for east, subtract for west. For river questions, trace the upstream name to the downstream name (Brahmaputra → Jamuna; Ganges → Padma).
Worked example
If it is 12:00 noon at 0° longitude, what is the time at 90°E? 90 ÷ 15 = 6 hours ahead, so the time is 18:00 (6 p.m.). Trap: subtracting instead of adding because 90°E is east of the prime meridian.
Environment and Disaster Management
Core concepts
Ecosystems and food chains, biodiversity, pollution types, climate change (greenhouse gases, global warming, mitigation vs. adaptation), and disaster management cycles (mitigation, preparedness, response, recovery). Bangladesh-specific hazards: cyclones, floods, riverbank erosion, salinity intrusion, and landslides.
Traps to expect
- Mitigation vs. adaptation: mitigation reduces greenhouse gas emissions; adaptation adjusts to impacts. Questions swap these constantly.
- Greenhouse gas ranking: CO₂ dominates by volume; methane is far more potent per molecule. Read whether the question asks about volume or potency.
- Disaster cycle order: preparedness precedes response; recovery follows response. Options often reverse the sequence.
- Ozone vs. greenhouse effect: ozone depletion and global warming are distinct problems with different causes.
- Food chain direction: energy flows from producer to consumer; arrows show energy flow, not "who eats whom" only.
Rule of thumb
Ask: does the action stop the cause (mitigation) or cope with the effect (adaptation)? Building embankments = adaptation; switching to solar power = mitigation. This single test resolves most climate questions.
Worked example
"Planting salt-tolerant rice varieties in coastal Bangladesh is an example of -" The action helps farmers cope with existing salinity, so it is adaptation, not mitigation. Trap: choosing mitigation because it involves agriculture and "green" imagery.