Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
1 nm = 10 Å
APPEARS IN
संबंधित प्रश्न
Calculate the focal length of a corrective lens having power +2.5 D.
What does sign of power (+ve or –ve) indicate?
A thin converging lens is formed with one surface convex and the other plane. Does the position of image depend on whether the convex surface or the plane surface faces the object?
The following diagram shows the object O and the image I formed by a lens. Copy the diagram and on it mark the positions of the lens LL’ and focus (F). Name the lens.
A stick partly immersed in water appears to be bent. Draw a ray diagram to show the bending of the stick when placed in water and viewed obliquely from above.
If the lens is of focal length 25 cm. Calculate the power of the lens.
Power of a lens is – 4D, then its focal length is
Assertion and reasoning type
- Assertion: Myopia is due to the increase in the converging power of eye lens.
- Reason: Myopia can be corrected with the help of concave lens.
The focal length of a concave lens is 20 cm. The focal length of a convex lens is 25 cm. These two are placed in contact with each other. What is the power of the combination? Is it diverging, converging or undeviating in nature?
The focal length of a double convex lens is equal to the radius of curvature of either surface. What is the refractive index of its material?
