Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Ray Optics

Question:

Match List I with List II

List I (Lens)

List II (Focal Length)

A. Double Convex Lens 

 I. \(f=\frac{R}{(1-{n}_{g}^{a})}\)

B. Plane Convex Lens

 II. \(f=\frac{R}{2({n}_{g}^{a}-1)}\)

C. Double Concave Lens

 III. \(f=\frac{R}{({n}_{g}^{a}-1)}\)

D. Plane Concave Lens 

IV. \(f=\frac{R}{2(1-{n}_{g}^{a})}\)

Choose the correct answer from the options given below: 

Options:

A-II, B-I, C-IV, D-III 

A-II, B-III, C-IV, D-I 

A-II, B-III, C-I, D-IV 

A-IV, B-III, C-II, D-I

Correct Answer:

A-II, B-III, C-IV, D-I 

Explanation:

$\text{Lens Formula } \frac{1}{f} = (\mu -1) (\frac{1}{R_1} -\frac{1}{R_2})$

$ \text{For double convex lens } R_1 = R , R_2 = -R$

$ \text{For plane convex lens } R_1 = \infty , R_2 = -R$

$ \text{For double concave lens } R_1 = -R , R_2 = +R$

$ \text{For plane concave lens } R_1 = \infty , R_2 = +R$