Q1: Which is colder, 32°F or 0°C?
The correct answer is: They are the same (32°F = 0°C).
Explanation: $32^\circ\text{F}$ is exactly equal to $0^\circ\text{C}$.
Q2: Water boils at °C and freezes at °F
The correct answer is: $100^\circ\text{C}$ (boils) and $32^\circ\text{F}$ (freezes).
Q3: Choose the correct one:
(i) Snowman can be made at temperature 25°F or 25°C
The correct answer is: 25°F.
Explanation: $25^\circ\text{F}$ is below freezing ($32^\circ\text{F}$), while $25^\circ\text{C}$ is warm.
(ii) In winter, we take a cup of coffee at 85°C / 85°F
The correct answer is: $85^\circ\text{C}$.
Explanation: $85^\circ\text{C}$ is a typical very-hot serving temperature; $85^\circ\text{F}$ ($\approx29.4^\circ\text{C}$) is only lukewarm.
Q4: Liquid used in thermometers is called
The correct answer is: Mercury.
Note: Alcohol is used in some low-temperature or colored thermometers, but the classic liquid is mercury.
Q5: Which thermometer has a greater range?
The correct answer is: Mercury thermometer.
Explanation: Mercury stays liquid over a wide temperature range and has good thermal conductivity, so mercury thermometers cover a larger range than many alcohol thermometers.
Q6: Convert $194^\circ\text{F}$ to the Celsius scale.
The correct answer is: $90^\circ\text{C}$.
Steps:
- Use $C=(F-32)\times\frac{5}{9}$.
- $C=(194-32)\times\frac{5}{9}=162\times\frac{5}{9}=90$.
Therefore $194^\circ\text{F}=90^\circ\text{C}$.
Q7: Convert $95^\circ\text{F}$ to the Celsius scale.
The correct answer is: $35^\circ\text{C}$.
Steps:
- $C=(95-32)\times\frac{5}{9}=63\times\frac{5}{9}=35$.
Therefore $95^\circ\text{F}=35^\circ\text{C}$.
Q8: Convert $80^\circ\text{C}$ to the Fahrenheit scale.
The correct answer is: $176^\circ\text{F}$.
Steps:
- Use $F=C\times\frac{9}{5}+32$.
- $F=80\times\frac{9}{5}+32=144+32=176$.
Therefore $80^\circ\text{C}=176^\circ\text{F}$.
Q9: Convert $0^\circ\text{C}$ to the Fahrenheit scale.
The correct answer is: $32^\circ\text{F}$.
Explanation: $F=0\times\frac{9}{5}+32=32$.
Q10: Fill in the blanks:
(i) The freezing point of water is
The correct answer is: $0^\circ\text{C}$.
(ii) The boiling point of water is
The correct answer is: $100^\circ\text{C}$.
(iii) The normal temperature of a healthy human body is
The correct answer is: $37^\circ\text{C}$ (≈$98.6^\circ\text{F}$).
Q11: On Monday the temperature was $39.5^\circ\text{C}$. On the next day, it decreased by $4.5^\circ\text{C}$. What was the temperature on the next day?
The correct answer is: $35.0^\circ\text{C}$.
Steps: $39.5-4.5=35.0$.
Q12: The maximum temperature of Noida last Monday was $37.2^\circ\text{C}$ while the minimum was $15.4^\circ\text{C}$. What was the difference in temperature?
The correct answer is: $21.8^\circ\text{C}$.
Steps: $37.2-15.4=21.8$.