| Description |
|---|
|
When all four legs of a spherometer are made to touch the
spehrical surface, the radiusof curvature(R) of the spherical
surface given by: R = (a2 ⁄ 6h) + (h ⁄ 2) Where 'a' is the main distance between the outer legs of the spherometer and 'h' is the highest of the central leg above of below the plane. |
| Readings no. | No of obs. | Linear Scale Reading (mm) | Circular Scale Divison | Least Count (mm) | Fractional part (mm) | Total reading (mm) | Mean (mm) |
|---|---|---|---|---|---|---|---|
| Base | 1 | ||||||
| Plate | 2 | ||||||
| 3 | 0.01 | ||||||
| Spherical | 1 | ||||||
| Glass | 2 | ||||||
| surface | 3 |
| Calculation |
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|
h = reading on spherical glass surface - reading on base
plate = h2 - h1 (mm) |
| least count = pitch / total number of divisions on circular scale (mm) |
|
measurement of 'a' Put the spherometer on the page, mark the 3 points where it touches the page, and measure the distance between these points, a1, a2, a3 (mm) |
| Mean Value = a1+a2+a3 / 3 mm |
| R = a2 ⁄ 6h + h ⁄ 2 (cm) (10 mm = 1cm) |
|
Result: The radius of curvature of given spherical surface is __ cm |
| Point | Explanation |
|---|---|