Horrok&;s apparatus determines Chloride which has to have a holding level of –
**Core Concept**
Horrock's apparatus is a device used to measure the chloride content in sweat or other bodily fluids. It is based on the principle that the chloride ion concentration is directly proportional to the electrical conductivity of the solution. The apparatus measures the electrical conductivity of the solution, which is then used to estimate the chloride concentration.
**Why the Correct Answer is Right**
The correct answer for the holding level of chloride in Horrock's apparatus is **6.2 mmol/L**. This value is used as a reference point to calibrate the apparatus and ensure accurate measurements. The apparatus works by passing a small current through the solution and measuring the resulting voltage. The chloride concentration is then calculated based on the measured voltage and the known conductivity of the solution at a reference chloride concentration of 6.2 mmol/L.
**Why Each Wrong Option is Incorrect**
* **Option A:** This value is too low and would result in inaccurate measurements.
* **Option B:** This value is too high and would also lead to incorrect results.
* **Option C:** This value is not a valid reference point for Horrock's apparatus.
**Clinical Pearl / High-Yield Fact**
It is essential to note that Horrock's apparatus is not a direct measure of chloride concentration but rather an indirect measurement based on electrical conductivity. This means that the accuracy of the results depends on the calibration of the apparatus and the reference values used.
**Correct Answer: D. 6.2 mmol/L**