What is the primary purpose of the slit in a spectroscope?

• A. To disperse the light into its component wavelengths
• B. To filter out ultraviolet radiation from the light source
• C. To allow only a narrow beam of light to enter, producing a sharp and well-defined spectrum
• D. To magnify the incoming light for better observation

Answer: (C)

Verified step by step guidance

1. Understand that a spectroscope is an instrument used to observe the spectrum of light by separating it into its component wavelengths.
2. Recognize that the slit in a spectroscope serves as the entry point for light into the device.
3. The slit allows only a narrow, well-defined beam of light to enter, which is crucial for producing a sharp and clear spectrum without overlapping or blurring of spectral lines.
4. This narrow beam ensures that the light is focused and collimated before it passes through the dispersing element (like a prism or diffraction grating), improving the resolution of the observed spectrum.
5. Therefore, the primary purpose of the slit is not to disperse light or filter specific wavelengths, but to control the light entering the spectroscope to produce a precise and well-defined spectral image.