Understanding the Weather Class 7 Notes | मौसम को समझना NCERT
Class 7 Social Science – Understanding the Weather
मौसम को समझना
Theme 1: India and the World – Land and the People
Understanding the Weather (English Explanation)
Weather refers to the day-to-day condition of the atmosphere at a particular place and time. It describes conditions such as temperature, rainfall, wind, humidity, and cloud cover. Weather can change within hours or even minutes.
For example, a day can begin with bright sunshine, become cloudy by afternoon, and end with rainfall. These short-term atmospheric changes are known as weather.
Difference Between Weather and Climate
Weather and climate are often confused, but they are different concepts:
- Weather is the condition of the atmosphere over a short period (hours or days).
- Climate is the average weather condition of a place over a long period (usually 30 years).
For example, saying “It is raining today” describes weather, while saying “Rajasthan is generally dry” describes climate.
Elements of Weather
1. Temperature
Temperature tells us how hot or cold the air is. It is measured using a thermometer and expressed in degrees Celsius (°C). High temperature indicates hot weather, while low temperature indicates cold weather.
2. Rainfall
Rainfall refers to the amount of rain received by a place during a specific period. It is measured in millimetres (mm). Rainfall affects agriculture, water supply, and daily life.
3. Wind
Wind is the movement of air from high-pressure areas to low-pressure areas. Wind direction and speed influence weather patterns such as storms and cyclones.
4. Humidity
Humidity refers to the amount of moisture present in the air. High humidity makes the weather feel sticky and uncomfortable, especially in summer.
5. Cloud Cover
Cloud cover refers to the amount of sky covered by clouds. Clouds play a key role in rainfall and temperature control.
Measuring Weather
Weather is studied using various instruments:
- Thermometer – measures temperature
- Rain gauge – measures rainfall
- Anemometer – measures wind speed
- Wind vane – shows wind direction
- Hygrometer – measures humidity
Why Understanding Weather Is Important
Understanding weather helps us:
- Plan daily activities
- Protect crops and livestock
- Prepare for natural disasters
- Ensure safety during travel
Farmers depend heavily on weather forecasts for sowing and harvesting crops. Weather information is also essential for disaster management.
मौसम को समझना (हिंदी व्याख्या)
मौसम किसी स्थान पर किसी विशेष समय में वायुमंडल की स्थिति को दर्शाता है। इसमें तापमान, वर्षा, हवा, नमी और बादलों की स्थिति शामिल होती है। मौसम में परिवर्तन बहुत तेजी से हो सकता है।
उदाहरण के लिए, सुबह धूप हो सकती है, दोपहर में बादल छा सकते हैं और शाम को बारिश हो सकती है। ऐसे अल्पकालिक परिवर्तन मौसम कहलाते हैं।
मौसम और जलवायु में अंतर
- मौसम – कम समय की वायुमंडलीय स्थिति
- जलवायु – लंबे समय (लगभग 30 वर्ष) का औसत मौसम
आज बारिश हो रही है – यह मौसम है। राजस्थान शुष्क प्रदेश है – यह जलवायु है।
मौसम के तत्व
1. तापमान
तापमान से पता चलता है कि वातावरण कितना गर्म या ठंडा है। इसे थर्मामीटर से मापा जाता है।
2. वर्षा
वर्षा किसी क्षेत्र में गिरने वाले पानी की मात्रा को दर्शाती है। यह कृषि और जल संसाधनों के लिए बहुत महत्वपूर्ण है।
3. पवन
पवन उच्च दाब से निम्न दाब की ओर चलती है। पवन की गति और दिशा मौसम को प्रभावित करती है।
4. आर्द्रता
वायु में उपस्थित जलवाष्प की मात्रा को आर्द्रता कहते हैं। अधिक आर्द्रता से उमस बढ़ती है।
5. बादल
बादल वर्षा और तापमान को नियंत्रित करने में महत्वपूर्ण भूमिका निभाते हैं।
मौसम मापने के उपकरण
- थर्मामीटर – तापमान
- वर्षामापी – वर्षा
- एनीमोमीटर – पवन की गति
- पवनदर्शी – पवन की दिशा
- हाइग्रोमीटर – आर्द्रता
मौसम को समझना क्यों आवश्यक है
मौसम की जानकारी से हमें दैनिक जीवन, कृषि, यात्रा और आपदा प्रबंधन में सहायता मिलती है।
Questions & Answers
A. Multiple Choice Questions (MCQs)
- Weather refers to – (a) long-term climate (b) daily atmospheric condition ✔ (c) seasons (d) vegetation
- Instrument used to measure rainfall – (a) Thermometer (b) Hygrometer (c) Rain gauge ✔ (d) Barometer
- Humidity means – (a) heat (b) wind (c) moisture in air ✔ (d) pressure
- Wind vane shows – (a) speed (b) direction ✔ (c) rainfall (d) humidity
- Temperature is measured in – (a) mm (b) km (c) °C ✔ (d) kg
- Climate is measured over – (a) days (b) months (c) years ✔ (d) hours
- Which affects farming most? – (a) Weather ✔ (b) Rocks (c) Soil (d) Transport
- Clouds help in – (a) rain ✔ (b) wind only (c) pollution (d) pressure
- Anemometer measures – (a) wind speed ✔ (b) rainfall (c) temperature (d) clouds
- Sticky weather is due to – (a) low humidity (b) high humidity ✔ (c) wind (d) rain
B. True / False
- Weather changes quickly – True
- Climate and weather are same – False
- Humidity means moisture in air – True
- Rain gauge measures wind – False
- Weather affects daily life – True
- Wind moves from low to high pressure – False
- Thermometer measures rainfall – False
- Clouds help in rainfall – True
- Climate is short-term – False
- Weather forecast helps farmers – True
C. Short Answer Questions
Q1. What is weather?
A. Weather is the day-to-day condition of the atmosphere.
Q2. Name two elements of weather.
A. Temperature and rainfall.
Q3. What is humidity?
A. Moisture present in air.
Q4. Which instrument measures wind speed?
A. Anemometer.
Q5. What is climate?
A. Long-term average weather condition.
Q6. Why is weather important for farmers?
A. It helps in crop planning.
Q7. What does rain gauge measure?
A. Rainfall.
Q8. What causes wind?
A. Difference in air pressure.
Q9. What is cloud cover?
A. Amount of sky covered by clouds.
Q10. Name one use of weather forecast.
A. Disaster preparedness.
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