A Kelvin thermometer and a Fahrenheit thermometer both give the same r

A Kelvin thermometer and a Fahrenheit thermometer both give the same reading for a certain sample. The corresponding Celsius temperature is about

301 °C
614 °C
276 °C
273 °C
This question was previously asked in
UPSC CISF-AC-EXE – 2019
The corresponding Celsius temperature is about 301 °C.
We are given that a Kelvin thermometer and a Fahrenheit thermometer give the same reading for a certain sample. Let this reading be x.
So, the temperature in Kelvin (K) is x, and the temperature in Fahrenheit (F) is x.
We need to find the corresponding temperature in Celsius (C).

The conversion formulas between these scales are:
1. Fahrenheit to Celsius: C = (F – 32) * 5/9
2. Kelvin to Celsius: C = K – 273.15 (or often approximated as C = K – 273)

Let’s use the exact conversion K = C + 273.15 and F = (9/5)C + 32.
Since K = x and F = x, we have:
x = C + 273.15 (Equation 1)
x = (9/5)C + 32 (Equation 2)

Equating the right sides of Equation 1 and Equation 2:
C + 273.15 = (9/5)C + 32

Rearrange the terms to solve for C:
273.15 – 32 = (9/5)C – C
241.15 = (9/5 – 5/5)C
241.15 = (4/5)C

C = (241.15 * 5) / 4
C = 1205.75 / 4
C = 301.4375

Rounding to the nearest whole number or considering the options, the corresponding Celsius temperature is about 301 °C.

The question asks for “about” the Celsius temperature, indicating an approximation is acceptable. Using the approximation C = K – 273 would yield C = 301.4375 – 0.15 ≈ 301.2875, still close to 301 °C. The unusual point where Kelvin and Fahrenheit scales read the same is 301.4375 in both K and °F.