PREVIOUSLY ASKED IN:
WBPSC Miscellaneous Preliminary 2019
Answer
-40°
Explanation
The Celsius and Fahrenheit temperature scales read exactly the same value at -40 degrees. This can be derived from the temperature conversion formula: C/5 = (F - 32)/9. If we set both C and F to the same unknown variable 'x', the equation becomes x/5 = (x - 32)/9. Solving for x yields 9x = 5x - 160, which simplifies to 4x = -160, resulting in x = -40. Thus, -40°C is equivalent to -40°F.
Key Points
- > The freezing point of water is 0°C or 32°F.
- > The boiling point of water under standard atmospheric pressure is 100°C or 212°F.
- > Normal human body temperature is approximately 37°C or 98.6°F.
- > Absolute zero, the lowest possible temperature, is -273.15°C or 0 Kelvin (0 K).
- > The SI unit for temperature is the Kelvin (K).
Additional Information
Temperature Scale Comparisons
| Temperature Point | Celsius (°C) | Fahrenheit (°F) | Kelvin (K) |
|---|---|---|---|
| Boiling point of water | 100° | 212° | 373.15 |
| Normal Body Temp | 37° | 98.6° | 310.15 |
| Freezing point of water | 0° | 32° | 273.15 |
| Equal Reading Point | -40° | -40° | 233.15 |
| Absolute Zero | -273.15° | -459.67° | 0 |
Memory Tips
- Minus Forty: -40° is the magic number where both commonly used scales (Celsius and Fahrenheit) intersect and show the exact same numerical reading.