Water — Class 7 Social Science

Take a timed mock test to prepare for your exams.

Chapter Mock Test

Total Marks:40
Duration:45 min
Total Questions:20
Difficulty:Mixed

Test Structure

  • Section A: 10 MCQs (1 mark each)
  • Section B: 6 Short Answer (3 marks each)
  • Section C: 2 Long Answer (5 marks each)

Before taking the test

  • Know the water cycle stages: Evaporation, Condensation, Precipitation, Collection — driven by the Sun
  • Remember water distribution: 97.3% saltwater, 2.7% freshwater, only about 1% usable
  • Average ocean salinity = 35 parts per thousand (35‰); higher with more evaporation, lower near river mouths
  • Waves: caused by wind; crest = highest, trough = lowest; water moves in circles, energy moves forward
  • Tsunami: caused by underwater earthquakes (NOT wind); 2004 Indian Ocean tsunami is a key example
  • Tides: caused by Moon and Sun gravitational pull; two high and two low tides daily
  • Spring tides = full/new moon (Sun, Moon, Earth in line = very high tides). Neap tides = quarter moon (at right angles = moderate)
  • Warm currents: equator to poles (Gulf Stream keeps Europe warm). Cold currents: poles to equator (can cause deserts)
  • Where warm and cold currents meet = great fishing grounds (e.g., Newfoundland)
  • Water conservation methods: rainwater harvesting, drip irrigation, fixing leaks, recycling water, planting trees

Key Concepts to Remember

Water Distribution

97.3% saltwater + 2% frozen + 0.7% usable = 100%. Only 1% is available for human use

Ocean Movements

Waves (wind) + Tides (Moon/Sun gravity) + Currents (temperature/wind) = Three types of ocean movement

Tides

Spring = Full/New Moon (in a line, very high). Neap = Quarter Moon (right angles, moderate)

Ocean Currents

Warm (equator to poles, bring rain) + Cold (poles to equator, can cause deserts). Meeting point = fishing grounds