Sun28November0333PM 4

Many processes we deal with in anaesthesia involve a relationship between one variable and another.

Which one of the following relationships is linear?

(Please select 1 option)

The relationship between a decrease in plasma concentration of an intravenous bolus of a drug with time for a single compartment model

The relationship between the pressure of a fixed mass of gas and its volume at a fixed temperature

The relationship between the junction potential and temperature in a thermocouple This is the correct answer

The relationship between efficacy and log-dose of a pure agonist on mu receptors Incorrect answer selected

The relationship between current and degrees from a mains electricity source

Explanation

A thermocouple is composed of two bonded wires of dissimilar metals, iron/constantan or copper/constantan (constantan is an alloy of copper and nickel). A thermojunction voltage is generated at the tip that is directly proportional to temperature (Seebeck effect).

All the other relationships are not linear.

The relationship between a decrease in plasma concentration of an intravenous bolus of a drug with time for a single compartment model is a washout exponential.

The relationship between current and degrees or time from a mains electricity source is a sine wave.

The relationship between efficacy and log-dose of a pure agonist on mu receptors is a sigmoid curve.

The relationship between the pressure of a fixed mass of gas and its volume (Boyle's law) at a fixed temperature is an inverse relationship and produces a hyperbolic curve.

Answer Statistics

1

16%

2

51%

3

22%

4

8%

5

5%

Times answered: 245