Question

A platinum wire is used as the thermometric substance in a resistance thermometer. What is the thermometric property being utilised here?

Options

• Volume expansion of a liquid

• Pressure of a gas at constant volume

• Electromotive force (EMF) between two metals

• Electrical resistance of a metal

Answer 1

Electrical resistance of a metal

Explanation:

In a resistance thermometer, the thermometric substance is a platinum wire, and the thermometric property is its electrical resistance, which changes measurably and predictably with temperature. This type of thermometer works over a wide range of −200 °C to 1200 °C and is known for very high accuracy.