Question

One calorie of heat is equivalent to 4.2 J. One BTU (British Thermal Unit) is equivalent to 1055 J. The value of one BTU in calorie is?
A) 251.2 cal
B) 200 cal
C) 263 cal
D) None of these

Answer 1

Hint: We need to find the value of One BTU in calories.
We know that:
$\begin{align}
  & 1cal=4.2J \\
 & 1BTU=1055J \\
\end{align}$
Use the given relation to find the value of one BTU in calorie.

Complete step by step answer:
As we have:
$\begin{align}
  & \Rightarrow 1cal=4.2J \\
 & \Rightarrow 1J=\dfrac{1}{4.2}cal \\
\end{align}$
So, value One BTU in calorie is:
$\begin{align}
  & 1 BTU=1055\times \dfrac{1}{4.2} \\
 & =251.19cal
\end{align}$

So, the correct answer is “Option A”.

Note:
Joule, unit of work or energy in the International System of Units (SI); it is equal to the work done by a force of one newton acting through one meter.
A calorie is the amount of heat needed to raise the temperature of one gram of water by one degree Celsius.
The British thermal unit (BTU or Btu) is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.