Heat and Temperature — REET Level 2 Science Notes
This page covers heat and temperature for REET Level 2 Science — the difference between the two, methods of heat transfer, sea and land breeze, and the effect of clothing colour — in exam-focused form. REET 2024 asked a complex matching question on this topic, so cause-and-effect reasoning is given special emphasis.
- 1 question in REET 2024
- Class 6-8 level content
- 6 min read
How REET actually asks this topic
REET 2024 asked a complex matching question on this topic, requiring you to connect clothing colour, season, and the timing of sea breeze/land breeze. In other words, REET is testing practical, cause-and-effect understanding here, not just definitions — so this page spells out the 'why' behind every concept, so you can answer any matching question with confidence.
The difference between heat and temperature
Temperature is the scale that measures how hot or cold an object is — in other words, it tells you how hot something is. It's measured with a thermometer, and it is a scalar quantity.
Heat is a form of energy that flows from an object at a higher temperature to one at a lower temperature. This flow continues until the temperatures of both objects become equal (thermal equilibrium). The SI unit of heat is the joule (J), while temperature is measured in Celsius, Fahrenheit, or Kelvin.
An example makes the difference clear — a cup of hot tea might have a high temperature, but a bucket of lukewarm water, having far more water in it, might actually contain more heat (thermal energy) overall. So temperature indicates the 'degree of hotness' of an object, while heat indicates the total thermal energy present in it — and this is exactly the distinction the exam tests again and again.
Types of thermometers and their ranges
- Clinical thermometer
- 35°C to 42°C; used to measure the human body's temperature (normal body temperature ≈ 37°C)
- Laboratory thermometer
- −10°C to 110°C; for general experimental use
- The general principle of measuring temperature
- The expansion and contraction of mercury or a coloured liquid inside a thermometer reflects the change in temperature
Three ways heat is transferred
| Method | Medium | Example |
|---|---|---|
| Conduction | Solids | A pan's handle heating up; heating one end of a metal rod heats the other end; metals are good conductors while wood and plastic are poor conductors (insulators) |
| Convection | Liquids and gases | Heated water rising to the top while cooler water sinks when boiling; warm air rising in a room |
| Radiation | Needs no medium at all | Heat travelling from the Sun to the Earth |
Conduction and convection need a medium, but radiation can happen even through a vacuum — which is exactly why the Sun's heat is able to cross empty space to reach the Earth.
Sea breeze and land breeze
During the day, land heats up faster than the sea, so the warm air above the land rises, and cooler air from the sea flows in to take its place — this is called a sea breeze, and it blows during the day.
At night, land cools down quickly, while sea water cools much more slowly; then, cooler air from the land begins to flow towards the sea — this is called a land breeze, and it blows at night. This difference happens because water's specific heat is higher than that of soil, so water heats up and cools down more slowly.
Clothing colour and heat
Dark-coloured clothes (like black) absorb more heat, which is why they are better in winter, helping keep the body warm. Light-coloured clothes (like white) reflect more heat, which is why they are more comfortable in summer, since the body absorbs less heat.
The same principle is applied to the roofs of homes and buildings too — in hot regions, roofs are often painted white or a light colour, so the Sun's heat is absorbed less and the interior stays cooler.
How to teach this to children
Classroom activity
Keep two identical bottles in the sun, one wrapped in black cloth and one in white, and after some time have students compare how warm each one feels, so they directly observe the link between colour and heat absorption. The result can also be measured with a thermometer and recorded numerically.
Teaching aids
Heat one end of a metal rod with a candle and stick butter or wax on the other end to directly demonstrate conduction. Along with this, dropping a coloured drop into water and heating it can also show convection currents.
Common misconception
Students often take heat and temperature to be the same thing; make it clear that temperature is the degree of an object's hotness, while heat is the energy that flows. Use an example to show that a large object can have more heat even at a lower temperature.
Assessment idea
Ask students, 'why do we wear black in winter and white in summer?' — this checks understanding of absorption versus reflection. They can also be asked to draw the timing and direction of sea breeze and land breeze.
Memory trick
Sea breeze = blows from sea to land during the day; land breeze = blows from land to sea at night. Remember it as — 'in the day the sea sends air to the land, at night the land sends air to the sea'. For colour, remember: 'dark absorbs, light reflects'. And for heat transfer: 'conduction in solids, convection in liquids-and-gases, and radiation even through empty space'.
REET 2024 question (with solution)
Question 121
Match the column X with the column Y : Column X: p. Time to prefer wearing dark coloured clothes; q. Time of blowing of the sea breeze; r. Time to prefer wearing light coloured clothes; s. Time of blowing of the land breeze Column Y: i. night time; ii. winters; iii. day time; iv. summers The correct answer is
- Ap – i, q – ii, r – iii, s – iv
- Bp – ii, q – iii, r – i, s – iv
- Cp – ii, q – iii, r – iv, s – i
- Dp – iv, q – i, r – ii, s – iii
Explanation
सर्दियों (ii) में गहरे रंग के कपड़े पहनना अच्छा है, क्योंकि गहरे रंग ऊष्मा अधिक अवशोषित करते हैं; गर्मियों (iv) में हल्के रंग के कपड़े, क्योंकि वे ऊष्मा परावर्तित करते हैं। दिन के समय (iii) स्थल जल्दी गर्म होता है, इसलिए समुद्र से स्थल की ओर समुद्र समीर बहती है; रात्रि (i) में स्थल जल्दी ठंडा होता है, इसलिए स्थल से समुद्र की ओर थल समीर बहती है। अतः p–ii, q–iii, r–iv, s–i।
Practice questions
Question 1
The normal human body temperature is approximately
- A42°C
- B37°C
- C25°C
- D100°C
Explanation
A normal human body's temperature is approximately 37°C (98.6°F).
Question 2
The range of a clinical thermometer is
- A−10°C से 110°C
- B35°C से 42°C
- C0°C से 100°C
- D37°C से 100°C
Explanation
A clinical thermometer is built only to measure human body temperature, so its range is 35°C to 42°C.
Question 3
The method of heat transfer that does not require any medium is called
- Aचालन
- Bसंवहन
- Cविकिरण
- Dस्थानांतरण
Explanation
Radiation can carry heat without needing any medium, as it does from the Sun to the Earth.
Question 4
During the day, the wind blowing at a seashore (sea breeze) flows in which direction?
- Aस्थल से समुद्र की ओर
- Bसमुद्र से स्थल की ओर
- Cऊपर से नीचे की ओर
- Dस्थिर, कोई दिशा नहीं
Explanation
During the day, land heats up quickly and sends warm air upward, and cooler air from the sea flows in to replace it, moving towards the land.
Question 5
Dark-coloured clothes are preferred in winter because they
- Aऊष्मा को परावर्तित करते हैं
- Bऊष्मा को अधिक अवशोषित करते हैं
- Cऊष्मा को रोकते नहीं
- Dहल्के होते हैं
Explanation
Dark-coloured clothes absorb more heat, which keeps the body warm, making them suitable for winter.
Question 6
If land heats up quickly during the day, how will the land behave at night?
- Aजल्दी ठंडा होना, जिससे थल समीर बहती है
- Bजल्दी गर्म रहना
- Cसमुद्र से धीमा ठंडा होना
- Dकोई परिवर्तन नहीं
Explanation
Land cools down just as quickly as it heats up, so at night a land breeze blows from the land towards the sea.
Question 7
Feeling heat while holding the handle of a hot pan is an example of which method of heat transfer?
- Aसंवहन
- Bविकिरण
- Cचालन
- Dवाष्पीकरण
Explanation
In a solid metal handle, heat travels from one end to the other by conduction.
Question 8
To directly demonstrate conduction to children, a teacher would choose which experiment as most suitable?
- Aधातु की छड़ के एक सिरे को गर्म कर दूसरे सिरे पर मोम पिघलते देखना
- Bपानी में रंग मिलाकर देखना
- Cकागज़ जलाना
- Dकपड़ों के रंग की तुलना करना
Explanation
Watching wax melt at one end of a metal rod when the other end is heated gives direct proof of heat flowing by conduction.
Question 9
Which of the following statements about heat and temperature is correct?
- Aऊष्मा व ताप एक ही राशि हैं
- Bताप ऊर्जा का रूप है, ऊष्मा नहीं
- Cऊष्मा सदा अधिक ताप वाली वस्तु से कम ताप वाली वस्तु की ओर बहती है
- Dकम ताप वाली वस्तु से अधिक ताप वाली वस्तु की ओर ऊष्मा बहती है
Explanation
Heat always flows from an object at a higher temperature to one at a lower temperature, until both reach the same temperature.
Question 10
The most common misconception students have in class is that they believe
- Aऊष्मा व ताप एक ही राशि हैं, केवल नाम अलग हैं
- Bतापमान बढ़ने पर हमेशा ऊष्मा घटती है
- Cचालन केवल गैसों में होता है
- Dविकिरण के लिए माध्यम आवश्यक है
Explanation
Students often think of heat (energy) and temperature (a measurement scale) as the same thing; the teacher should clarify this difference with clear examples.
Frequently asked questions
What is the basic difference between heat and temperature?+
Temperature is a measure of hotness (how hot something is), while heat is the energy that flows from a higher temperature to a lower one; the two also have different units.
What is the range of a clinical thermometer?+
35°C to 42°C, because it's built only to measure human body temperature, which normally stays around 37°C.
When does a sea breeze blow?+
A sea breeze blows during the day, from the sea towards the land, because the land heats up faster and sends warm air upward, and cooler air from the sea flows in to take its place.
Why are dark-coloured clothes worn in winter?+
Dark-coloured clothes absorb more heat, which keeps the body warmer in winter; light colours, in contrast, reflect heat and keep you cooler in summer.
What level of question does REET ask on heat?+
Often matching and cause-and-effect type, as in the REET 2024 question that linked colour, season and breeze; that's why understanding the 'why' behind each concept matters.
How is radiation different from the other two methods?+
Conduction and convection both need a medium (solid, liquid, or gas), while radiation can carry heat even without any medium, as it does from the Sun to the Earth.
Why isn't a laboratory thermometer used to measure body temperature?+
A laboratory thermometer's range (−10°C to 110°C) is very wide, which makes it hard to read small changes around the body's normal 37°C accurately — that's why a separate clinical thermometer is made.
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Change Log
- 17 September 2026 — English page published — mirrors the fact-checked Hindi page, independently bilingual-accuracy checked