to determine the focal length of a convex lens by u-v method
Answers
Answered by
3
The equation connecting the distance between mirror and object (u), distance between mirror and image (v), and the focal length of the mirror (f) is called mirror formula.

Or ; The focal length of the concave mirror,

Focal length by graphical method
From u-v graph :
We can measure the focal length of the given concave mirror graphically by plotting graph between u and v. For this, plot a graph with u along X axis and v along Y axis by taking same scale for drawing the X and Y axes. A curve is obtained. The point at which the bisector meets the curve gives the radius of curvature (R).
Now focal length can be calculated from the relation, R = 2f.
From 1/u – 1/v graph :
We can also measure the focal length by plotting graph between 1/-u and 1/v. Plot a graph with 1/u along X axis and 1/v along Y axis by taking same scale for drawing the X and Y axes. The graph is a straight line intercepting the axes at A and B.
The focal length can be calculated by using the relations, OA=OB= 1/f.

Or ; The focal length of the concave mirror,

Focal length by graphical method
From u-v graph :
We can measure the focal length of the given concave mirror graphically by plotting graph between u and v. For this, plot a graph with u along X axis and v along Y axis by taking same scale for drawing the X and Y axes. A curve is obtained. The point at which the bisector meets the curve gives the radius of curvature (R).
Now focal length can be calculated from the relation, R = 2f.
From 1/u – 1/v graph :
We can also measure the focal length by plotting graph between 1/-u and 1/v. Plot a graph with 1/u along X axis and 1/v along Y axis by taking same scale for drawing the X and Y axes. The graph is a straight line intercepting the axes at A and B.
The focal length can be calculated by using the relations, OA=OB= 1/f.
Similar questions