CBSE Class 8 Answered
A convex lens of N =1.5 and focal length 0.2m is immersed in water of R.I.=1.33..calculate the change in power of the lens
Asked by ampoluharitha | 28 Dec, 2018, 08:53: PM
Expert Answer
Initial Power of lens = 1/0.2 = 5 Diopter
let us get the radius of curvature of the given lens from lens makers formula : 
where f is focal length, μ is refractive index, Rs are radii of curvature.
from (1), by substituting values for f and μ, we get, 
....................(2)
....................(2)when the lens is immersed in liquid, refractive index becomes = 1.5/1.33 = 1.128
hence power of lens when it is immersed in liquid, using eqns.(1) and (2) : (1.128-1)×10 = 1.28 Diopter
Change in power = 5 -1.28 = 3.72 Diopter
Answered by Thiyagarajan K | 29 Dec, 2018, 09:13: AM
Application Videos
-
Solving Linear Equations in one variable
This video explains the method of finding the solutions of given linear equ... -
Linear Equations to Simpler Form
This video explince the concept of Linear Equations to Simpler Form. -
Equations Reducible to the Linear Form
This video explains the concept of Equations Reducible to the Linear Form. -
Sum of the Measures of the Exterior Angles of a Polygon ...
This video explains the method of finding number of sides of a polygon if t... -
Grouped Frequency Distribution Table
This video explains the method of constructing the Grouped Frequency Distri...
Concept Videos
-
Construction of Rhombus
Construction of rhombus given side and angle, both diagonals -
Construction of squares and rectangles
construction of square given side and diagonals,construction of rectangles -
Quadrilaterals
Definition, elements, angle sum property, classification of quadrilaterals -
Surface Area: Cubes and Cuboids
cubes and cuboids, finding their surface area -
Bar Graphs and Histograms
bar graph, histogram their interpretation,comparison of the two
CBSE 8 - Maths
Asked by biswajitpatel88 | 10 May, 2024, 10:49: AM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by biswajitpatel88 | 10 May, 2024, 10:49: AM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by seemachaubey1987 | 05 May, 2024, 09:41: AM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by ptech3383 | 04 May, 2024, 06:10: PM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by sarkarchaitali4001 | 02 May, 2024, 04:11: PM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by jaiswal445512 | 01 May, 2024, 05:42: AM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by jigmetyangchen13 | 28 Apr, 2024, 02:33: PM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by chauhannaman12b | 25 Apr, 2024, 09:33: PM
ANSWERED BY EXPERTCBSE 8 - Maths
Asked by gk9941740 | 23 Apr, 2024, 05:13: PM
ANSWERED BY EXPERT
