Thermal Properties of Matter - Result Question 9

«««< HEAD:content/english/neet-pyq-chapterwise/physics/thermal-properties-of-matter/thermal-properties-of-matter-result-question-9.md

9. A centigrade and a Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers $140^{\circ}$. What is the fall in temperature as registered by the Centigrade thermometer?

======= ####9. A centigrade and a Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit thermometer registers $140^{\circ}$. What is the fall in temperature as registered by the Centigrade thermometer?

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/thermal-properties-of-matter/thermal-properties-of-matter—result-question-9.md (a) $80^{\circ}$

(b) $60^{\circ}$

(c) $40^{\circ}$

(d) $30^{\circ}$

[1990]

Topic 2: Calorimetry & Heat Transfer

Show Answer

Answer:

Correct Answer: 9. (c)

Solution:

  1. (c) Using $\frac{F-32}{180}=\frac{C}{100}$

$\Rightarrow \frac{140-32}{180}=\frac{C}{100}$

$\Rightarrow C=60$

Temperature of boiling water $=100^{\circ} C$

We get, fall in temperature $=100-60=40^{\circ} C$

Centigrade (c) Fahrenheit (F) and Kelvin (K) scales of temperature are related as

$ \begin{aligned} & \frac{C-0}{100}=\frac{F-32}{212-32} \\ & =\frac{K-273.15}{373.15-273.15} \end{aligned} $