Viscometer
Anemometer
Spectroscope
Pyknometer
Answer is Right!
Answer is Wrong!
The answer is D. Pyknometer.
A viscometer is an instrument used to measure the viscosity of a fluid. An anemometer is an instrument used to measure wind speed. A spectroscope is an instrument used to study the spectrum of light emitted by a substance. A pyknometer is an instrument used to measure the density of a liquid or solid.
The pyknometer is the only instrument that does not measure a physical property of a fluid. The other three instruments measure the viscosity, wind speed, and spectrum of light, respectively.