To answer this question, you need to understand what a Geiger counter is used for.
A Geiger counter is a device used to measure radioactivity. It detects and counts ionizing radiation, such as alpha particles, beta particles, and gamma rays, emitted by radioactive materials.
Let's go through each option to understand why it is correct or incorrect:
Option A) Earthquake strength - This option is incorrect because a Geiger counter is not used to measure earthquake strength. Earthquake strength is typically measured using seismographs.
Option B) Radioactivity - This option is correct because a Geiger counter is specifically designed to measure radioactivity.
Option C) Acidity - This option is incorrect because a Geiger counter is not used to measure acidity. Acidity is typically measured using pH meters or indicators.
Option D) Wind Speed - This option is incorrect because a Geiger counter is not used to measure wind speed. Wind speed is typically measured using anemometers or wind gauges.
The correct answer is B) Radioactivity. This option is correct because a Geiger counter is specifically designed to measure radioactivity.