Why correction of curvature is always considered as a negative?
Jamb and corbel are two different technical terms used in masonry. The difference in between jam and corbel are discussed below; 1) Definition: Jamb- A finished vertical sides of the opening of Window or door is called as a jamb. corbel- A supporting a stone projecting outside from the wall is calleRead more
Jamb and corbel are two different technical terms used in masonry.
The difference in between jam and corbel are discussed below;
1) Definition:
- Jamb– A finished vertical sides of the opening of Window or door is called as a jamb.
- corbel- A supporting a stone projecting outside from the wall is called a corbel.
2) Function:
- Jamb– jamb is provided at the recess to receive the frames of doors and frames of Windows
- Corbel– corbel is provided to give support to joist, truss and weather shed.
- Jamb has two types:
- Plane jamb
- Splayed jamb
- Mostly Corbel is moulded to give ornamental treatment to the structure.
- The corbel should be extended at least two-thirds of their length into the wall hence they can’t overturn out of the wall.
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Here, consider lens or mirror at the origin. Now, all the distances measured in the direction of incident rays are positive and distances measured in the direction opposite to the direction of incident rays are negative. All distances have to be measured from the lens or mirror. For example object dRead more
Here, consider lens or mirror at the origin. Now, all the distances measured in the direction of incident rays are positive and distances measured in the direction opposite to the direction of incident rays are negative. All distances have to be measured from the lens or mirror. For example object distance measured from lens or mirror is measured in the direction opposite to direction of incident rays hence, in these case object distance u is negative. The paraxial parallel rays are focused on the right hand side of convex lens. See, this distance f is measured in the direction of incident rays . Hence, focal length of convex lens is positive. But, we can see that focal length of concave mirror is negative. It’s radius of curvature is also negative. The radius of curvature of first surface of convex lens is positive, but radius of curvature of it’s second surface is negative. You can see that radius of curvature and focal length of concave mirror are negative.
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