20 Important Words (with Hindi meanings)

• Temperature — तापमान; गरमी-सरदी की माप
• Thermometer — तापमापी; तापमान नापने का यंत्र
• Clinical Thermometer — रोगी का शरीर ताप नापने वाला यंत्र
• Laboratory Thermometer — प्रयोगशाला में प्रयोग होने वाला तापमापी
• Mercury — पारा; द्रव धातु जो तापमापी में प्रयोग होता है
• Bulb — तापमापी का निचला भाग जिसमें पारा भरा होता है
• Capillary tube — पतली नली जिसमें पारा ऊपर-नीचे चलता है
• Degree Celsius (°C) — तापमान की इकाई
• Freezing point — 0°C; पानी जमने का तापमान
• Boiling point — 100°C; पानी उबलने का तापमान
• Fahrenheit (°F) — तापमान की दूसरी इकाई
• Kelvin (K) — वैज्ञानिक तापमान इकाई
• Normal body temperature — सामान्य मानव शरीर तापमान (37°C)
• Expansion — फैलना; गर्मी में पारा ऊपर चढ़ता है
• Contraction — सिकुड़ना; ठंड में पारा नीचे आता है
• Range — सीमा; न्यूनतम से अधिकतम तापमान माप
• Precaution — सावधानी; तापमापी का सही प्रयोग
• Scale — अंकित रेखाएँ जो तापमान दिखाती हैं
• Calibration — नाप को सही करना
• Heat — ऊष्मा; ताप का कारण

Important Notes

• Temperature tells how hot or cold a body is.
• Thermometers measure temperature in °C, °F, or K.
• Clinical thermometer measures human body temperature (range 35°C to 42°C).
• Laboratory thermometer measures temperature in experiments (range -10°C to 110°C).
• Normal human body temperature is 37°C or 98.6°F.
• Water freezes at 0°C and boils at 100°C.
• Mercury expands with heat and rises in the capillary tube.
• Precautions: Read thermometer at eye level, hold upright, do not shake violently.

20 One-Word Answers

1. Unit of temperature in SI?
   Kelvin (K).
2. Freezing point of water?
   0°C.
3. Boiling point of water?
   100°C.
4. Normal human body temperature?
   37°C.
5. Instrument for measuring temperature?
   Thermometer.
6. Range of clinical thermometer?
   35°C to 42°C.
7. Range of laboratory thermometer?
   -10°C to 110°C.
8. Liquid used in thermometer?
   Mercury.
9. Unit of Fahrenheit scale?
   °F.
10. Thermometer used by doctors?
    Clinical thermometer.
11. Thermometer used in labs?
    Laboratory thermometer.
12. Temperature at which water changes to ice?
    0°C.
13. Temperature at which water changes to steam?
    100°C.
14. SI unit symbol of temperature?
    K.
15. Colour of liquid metal mercury?
    Silvery-white.
16. Precaution while reading thermometer?
    Eye-level reading.
17. What is 98.6°F in Celsius?
    37°C.
18. What is 0 K called?
    Absolute zero.
19. Who invented thermometer?
    Galileo (early version).
20. What expands in thermometer?
    Mercury column.

10 Very Short Answers

1. Why does mercury rise in thermometer?
   Because it expands on heating.
2. Why is mercury used in thermometers?
   It expands uniformly, visible and doesn’t stick.
3. What is absolute zero?
   0 K; lowest possible temperature.
4. Why clinical thermometer has kink?
   To hold mercury in place for reading.
5. Give conversion formula °C to °F.
   \( F = \frac{9}{5}C + 32 \).
6. Give conversion formula °F to °C.
   \( C = \frac{5}{9}(F - 32) \).
7. Who needs a laboratory thermometer?
   Scientists and students in experiments.
8. What is the normal temperature of a healthy person in °F?
   98.6°F.
9. At what temperature does mercury freeze?
   -39°C.
10. At what temperature does mercury boil?
    357°C.

10 Short Answer Questions

1. Explain how a thermometer works.
   When temperature increases, mercury expands and rises in the capillary tube. Scale shows the reading.
2. Differentiate between clinical and laboratory thermometer.
   Clinical: 35–42°C range, has a kink, used for body temperature. Laboratory: -10–110°C range, no kink, used in experiments.
3. Why do we not use laboratory thermometer for measuring body temperature?
   Because its range is too wide and it has no kink to hold mercury.
4. Why should we not hold bulb of thermometer with hand while reading?
   Heat of hand may affect reading.
5. Why is water not used instead of mercury?
   Water evaporates, expands unevenly and freezes easily.
6. State the precautions for using clinical thermometer.
   Shake before use, keep bulb under tongue/arm, read at eye level, disinfect after use.
7. Write relation between Celsius and Kelvin.
   K = °C + 273.
8. Why is temperature important in daily life?
   It helps in cooking, weather forecast, medical care, scientific work etc.
9. Explain how to measure body temperature with clinical thermometer.
   Shake to bring mercury below 35°C, place bulb under tongue, wait 1 minute, read scale at eye level.
10. What precautions are taken while storing thermometers?
    Keep vertical in case, avoid jerks, don’t expose to high heat.

Important Equations (MathJax)

Celsius to Fahrenheit: $$F = \tfrac{9}{5}C + 32$$

Fahrenheit to Celsius: $$C = \tfrac{5}{9}(F - 32)$$

Kelvin to Celsius: $$K = C + 273$$