Topics:
Animal Nutrition, Animal Refresher
Calorie to Joule Conversion
1 calorie is equal to ______ Joule.
- 0.23
- 2.18
- 4.18 — Correct Answer
- None
Explanation:
Correct Answer: 4.18 Joules
1 calorie (thermochemical) = 4.18 Joules (also written as 4.184 J). This is the internationally accepted conversion factor between the calorie (CGS system) and joule (SI system). In animal nutrition, the Mcal (Megacalorie) and MJ (Megajoule) are more commonly used for feed energy values.
Energy Unit Conversions in Animal Nutrition
| Conversion | Value |
|---|---|
| 1 calorie → Joules | 4.18 J (or 4.184 J) |
| 1 kcal → kJ | 4.18 kJ |
| 1 Mcal → MJ | 4.18 MJ |
| 1 Joule → calories | 0.239 cal (≈ 0.24) |
| 1 kg TDN → Digestible Energy | 4.4 Mcal/kg |
| 1 kg TDN → Metabolic Energy | 3.6 Mcal/kg |
Historical Context
- The calorie was defined as the heat needed to raise 1 g of water by 1°C at 15°C.
- The joule is the SI unit of energy: 1 J = 1 N·m = 1 kg·m²/s².
- Modern animal nutrition increasingly uses MJ (Megajoules) instead of Mcal.
Why Other Options Are Wrong
- 0.23 → this is the reverse: 1 J = 0.239 cal; not 1 cal = 0.23 J.
- 2.18 → not a recognized calorie-joule conversion; has no physical basis.
- None → 4.18 J is the correct and standard conversion.
📚 About this Topic — Animal Nutrition
This multiple choice question is from Animal Nutrition, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Nutrition to strengthen your preparation.
