Question

the light inlet slit of a spectroscope should be ideally wide to create spectral lines, which are easier to measure. 1 mm; narrower 1 cm; wider 1 cm; narrower 1 m; wider

Explanation:

A spectroscope's inlet slit width affects spectral line width. A 1 - mm slit is appropriate as 1 cm and 1 m are too large. Narrower lines (from a narrow slit) are easier to measure as they have less overlap and better resolution.

Answer:

1 mm; narrower