00:01
A concave mirror of radius 25 cm, that means focal name 12 .5 cm.
00:07
We have to find the nature of image at 45 cm, 25 cm and 5 cm, respectively.
00:15
For that, we will use the help of mirror formula.
00:19
Mirror formula is 1 divided by v plus 1 divided by u is equal to 1 divided by f, where b is the image distance u is the object distance and f represents the focal length so we will be equal to f multiplied by u divided by u minus f this is extremely generalized equation now we will put all the value of object distance in this equation and try to find the value of image distance.
01:02
For example, for question number a, we have been given that the object distance u is minus 45 centimeters.
01:11
So we will put it in this equation 1 and we get value of image distance b as minus 17 .3 centimeters.
01:23
To find exactly the orientation of image, we have to also find the magnification given by m is equal to minus v divided by u.
01:38
So we can see that u and v both are negative...