Which of the following devices is commonly used to precisely measure the wavelength of light?

• A. Spectrometer
• B. Voltmeter
• C. Barometer
• D. Calorimeter

Answer: (A)

Verified step by step guidance

1. Understand the purpose of each device listed: A voltmeter measures electric potential difference, a barometer measures atmospheric pressure, a calorimeter measures heat changes in chemical reactions, and a spectrometer measures properties of light, including wavelength.
2. Recall that measuring the wavelength of light requires analyzing the light's spectrum, which involves separating light into its component wavelengths.
3. Recognize that a spectrometer is specifically designed to measure the intensity and wavelength of light by dispersing it through a prism or diffraction grating.
4. Conclude that among the given options, the spectrometer is the device commonly used to precisely measure the wavelength of light.
5. Therefore, the correct choice is the spectrometer because it directly relates to the measurement of light wavelengths, unlike the other devices.