An E Clylinder of oxygen contains approximately how many litres?
**Core Concept**
The question tests knowledge of medical gas cylinders, specifically the volume of oxygen contained in an E cylinder. Oxygen therapy is a crucial aspect of medical care, and understanding the capacity of oxygen cylinders is essential for **oxygen therapy management**.
**Why the Correct Answer is Right**
An E cylinder is a small, portable cylinder used for **oxygen supply** in medical settings. It contains approximately 660 litres of oxygen, making it a convenient option for patients requiring **supplemental oxygen**. The volume of oxygen in an E cylinder is calculated based on the **cylinder volume** and **pressure**.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it significantly underestimates the volume of oxygen in an E cylinder.
**Option B:** This option overestimates the volume, as E cylinders do not contain this much oxygen.
**Option D:** This option is also incorrect, as it does not accurately represent the volume of oxygen in an E cylinder.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the volume of oxygen in a cylinder can vary depending on the **cylinder size** and **type**. Knowing the correct volume is crucial for **oxygen therapy planning** and ensuring patient safety.
**Correct Answer:** C. 660 litres.