A compound lens has been formed by joinined a convex and a concave lens, each of focal length 30 cm. what is the focal length of the combination? What will be the power ?
1 Answers
Talk Doctor Online in Bissoy App
An eye-piece consists of a concave lens of focal length 2f and a convex lens of focal length 3f separted by a distance `(f)/(2)`. They are of the same
Correct Answer - Free from chromatic aberration but not spherical, yes
2 Answers 1 views
Calculate the focal length of a convex lens of crown glass of dispersive power 0.012 and concave lens of dispersive power 0.020 that from an achromati
Correct Answer - `r_("common")=1.11 m,0.644m`
2 Answers 2 views
The redius of curvature of the convex face of a plano-convex lens is 12cm and its refractive index is 1.5. a. Find the focal length of this lens. The
Correct Answer - (a) `+24 cm`; (b) `- 36cm` (c) `12 cm`(d) `- 180 cm`
2 Answers 1 views
An object is placed 20 cm to the left of a convex lens of focal length 10 cm. If a concave mirror of focal length 5cm is placed 30 cm to the right of
Correct Answer - The image coincides with the object
2 Answers 1 views
A concave lens of focal length 20 cm is placed 15 cm in front of a concave mirror of radius of curvature 26 cm and further 10 cm away from the lens is
Correct Answer - 140 cm in front of the lens
2 Answers 9 views
A convex lens of crown glass is perfectly cemented to a plano-concave lens of flint glass to form an achromatic combination of power `div 5D`. Calcula
Correct Answer - `8.6cm, 12 cm`
2 Answers 2 views
A convex lens of focal length `15 cm` is placed in front of a convex mirror. Both are coaxial and the lens is `5 cm` from the apex of the mirror. When
Correct Answer - 55 cm
2 Answers 1 views
The focal length of a concave-convex lens of radii of curvature 5 cm and 10 cm is 20 cm. what will be its focal length in water ? Given `.^(a)mu_(w) =
Correct Answer - `-80 cm`
2 Answers 2 views
A concave lens focal length 10 cm is placed on the axis of concave mirror of 10 cm radius at a distance of 5 cm from the mirror. An object is placed s
Correct Answer - 10 cm from the lens
2 Answers 1 views
Find the focal length and power of a convex lens, which when placed in contact with a concave lens of focal length `25 cm` forms a real image `5` time
Correct Answer - 10 cm, 10D
2 Answers 1 views