# What is the Temperature of the Triple-point of Water on an Absolute Scale Whose Unit Interval Size is Equal to that of the Fahrenheit Scale? - Physics

What is the temperature of the triple-point of water on an absolute scale whose unit interval size is equal to that of the Fahrenheit scale?

#### Solution 1

Let TF be the temperature on Fahrenheit scale and TK be the temperature on absolute scale. Both the temperatures can be related as:

(T_1 - 32)/180 = (T_K - 273.15)/100 ... (i)

Let TF1 be the temperature on Fahrenheit scale and TK1 be the temperature on absolute scale. Both the temperatures can be related as:

(T_eta - 32)/180 = (T_(K1) - 273.15)/100   ...(ii)

It is given that:

TK1 – TK = 1 K

Subtracting equation (i) from equation (ii), we get:

(T_(F1)- T_F)/180 =(T_(K1) - T_K)/100 = 1/100

T_(F1) - T_F = (1xx 180)/100 =  9/5

Triple point of water = 273.16 K

∴Triple point of water on absolute scale = 273.16xx 9/5 = 491.69

#### Solution 2

The Fahrenheit scale and Absolute scale are related as

(T_F - 32)/180 = (T_K-273)/100

For another set of temperature T'_F and T'_K'

(T'_F - 32)/180 = (T'_K - 273)/100

Subtracting i from ii

(T'_F - T_F)/180 = (T'_k -T_K)/100

:. T'_F - T_F = 180/100 (T'_K - T_K)

For  T'_K - T_K = 1K

T'_F - T_F = 180/100

:. For a temperature of triple point i.e 273.16 K the temperature on the new scale is

= 273.16 xx 180/100 = 491.688

Concept: Temperature and Heat
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#### APPEARS IN

NCERT Class 11 Physics Textbook
Chapter 11 Thermal Properties of Matter
Q 4.4 | Page 294