Basic Maths and Units and DimensionsHard
Question
An object is placed in front of an equiconvex lens with refractive index 1.5 and radius of curvature 30cm. Surface which is away from object is polished. Find the distance of object from lens so that object and image concide :-
Options
A.10 cm
B.20 cm
C.15 cm
D.40 cm
Solution
f′ =
=
= 7.5 cm
Concave mirror
u = 2f′ = 2 × 7.5 = 15 cm
Create a free account to view solution
View Solution FreeTopic: Basic Maths and Units and Dimensions·Practice all Basic Maths and Units and Dimensions questions
More Basic Maths and Units and Dimensions Questions
At a given instant, ratio of numbers of active nuclei in two different samples is 6 : 1. Their half lives are 3 hours an...Two physical quantities of which one is a vector and the other is a scalar having the same dimensional formula are :...Three charges q, 2q and 4q are placed on straight line at equal distances, then ratio of the force exerted by q on 4q an...A table fan, rotating at a speed of 2400 rpm is switched off and the resulting variation of the rpm with time is shown i...Two spheres P and Q of equal radii have densities ρ1 and ρ2, respectively. The spheres are connected by a mass...