Question Detail
Question
A diffraction grating has 20,000 lines per inch. What is the approximate spacing 'd' between the slits in meters? (Given: 1 inch = 0.0254 meters)
Correct Answer
Option A is the correct answer.
Detailed Explanation
The spacing 'd' is the inverse of the number of lines per unit length. First, convert lines per inch to lines per meter: 20,000 lines/inch * (1 inch / 0.0254 m) = 787,401.57 lines/m. Then, d = 1 / (787,401.57 lines/m) = 1.27 x 10-6 m. Alternatively, d = (0.0254 m) / (20,000 lines) = 1.27 x 10-6 m.
Hint
Remember that 'd' is the distance between adjacent lines. If there are 20,000 lines in one inch, then each line spacing is 1 inch divided by 20,000.