Question

1 Kcal=___________
A. 418.4 joule
B. 4184 joule
C. 4.184 joule
D. 41.84 joule

Answer 1

Hint: Calorie and Joules are units of heat energy. Calorie (cal) is the C.G.S unit of heat energy while Joules (J) is S.I. unit of heat energy.

Complete step-by-step answer:
The calorie (cal) is C.G.S unit of heat energy. It is defined as the energy required to raise the temperature of 1 gm of water by 1° C or by 1K. S.I. The unit of heat energy is Joules (J). 1cal = 4.184 Joules.
We know that,
1 kcal =1000 cal
So $1kcal=1000\times 4.184$ joule
$\Rightarrow 1kcal=4184$ joule
Hence, the correct answer is option B i.e. 4184 joules.

So, the correct answer is “Option B”.

Additional Information:
There are two types of Calorie: A small calorie (cal) is the amount of energy required to raise the temperature of 1 gram of water by 1°C or by 1K. A large calorie (kcal) is the amount of energy required to raise the temperature of 1 kilogram of water by 1°C or by 1K. 1 kcal is equal to 4184 Joules.
If 1 gram of water is given 2 cal, its temperature will go up 2 degrees. It takes 80 cal to melt 1 gram of ice.
Another unit of heat energy is Btu (British thermal unit). It is defined as the amount of energy required to increase the temperature of 1 pound of water by 1° F. It is used to measure the heat produced by heating systems or heat removed by air-conditioning systems.
1 Btu = 1055 Joules
1 Btu= 252 cal

Note: The most common units of heat are Btu (British Thermal Unit). Calorie and Joules. 1 small kilocalorie (kcal) is equal to 1 large food calorie (Cal). 1 small kilocalorie (kcal) is equal to 1000 small calories (cal).