Sign convention for plano concave lens ,convex concave lens
Asked by Harshit | 22nd Jan, 2017, 11:22: AM
Sign convention for reflection by Lens
In this convention, the pole (P) of the mirror is taken as the origin. The principal axis of the mirror is taken as the x-axis (X′X) of the coordinate system.The distances are measured from the optical centre.
The sign convention is as follows:
- The object is always placed to the left of the mirror. This implies that the light from the object falls on the mirror from the left-hand side.
- All distances parallel to the principal axis are measured from the pole of the mirror.
- All distances measured to the right of the origin (along +x-axis) are taken as positive, while those measured to the left of the origin (along −x-axis) are taken as negative.
- Distances measured perpendicular to and above the principal axis (along +y-axis) are taken as positive.
- Distances measured perpendicular to and below the principal axis (along −y-axis) are taken as negative.
- According to the sign convention, the focal length of a convex lens is positive and that of a concave lens is negative.
Note: The sign conventions for all types of lenses is the same. Infact the sign convention for spherical mirrors and lenses is also same (Except for the focal length).
Answered by Yashvanti Jain | 23rd Jan, 2017, 11:57: AM
- beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12 cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20 cm, and (b) a concave lens of focal length 16 cm?
- Plz solve this
- What is the position of object in photographic camera
- 'As an object is slowly brought from infinity to the focus of convex lens, the image travels from the focus to infinity.' Show this with the help of diagram with five different positions of the object.
- An object placed on ameter scale at 8 cm mark was focused on a white screen placed at 92 cm mark,using a converginglens placed on the meter scale at 50 cm mark. a) find the focal length of the converging lens b) find the position of the image formed if the object is shifted towards the lens at a position of 29 cm c) state the nature of image formed if the object is further shifte towards the lens.
- The object distance of a lens is 30 cm and the image distance is 10 cm find the magnificence of the lens with the help of this decide whether the size of the image is small or big than the size of the object ?
- image formed by a simple microscope
Kindly Sign up for a personalised experience
- Ask Study Doubts
- Sample Papers
- Past Year Papers
- Textbook Solutions
Verify mobile number
Enter the OTP sent to your number