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:
Answer & explanation
Correct answer: option 2
$\text{Lens Formula } \frac{1}{f} = (\mu -1) (\frac{1}{R_1} -\frac{1}{R_2})$
$ \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$