Question

The diagrams showing the correct path of the ray after passing through the

(a) II and III only

(b) I and II only

(c) I, II and III

(d) I, II and IV

Answer 1

Answer:

B is the answer please put me brainliest

Answer 2

Given:  Figures representing various ray diagrams for convex lens

To find: Correct ray diagram

Solution:

Let us consider each ray diagram one by one.i

(I) In this figure, the ray passes through the optical centre of the lens undeflected. This diagram is correct as a ray passing through centre of lens will continue on its path.

(II) In this diagram, we will solve the situation mathematically using the lens formula:

                                        $\frac{1}{v}$ - $\frac{1}{u}$ = $\frac{1}{f}$                            (1)

Here, u = ∞, f = $F_{}$, v is to be calculated. Substituting these values in (1)

                                   $\frac{1}{v}$ - $\frac{1}{∞}$ = $\frac{1}{F_{} }$

                          ⇒     $\frac{1}{v}$ - 0 = $\frac{1}{F_{} }$

                          ⇒          $\frac{1}{v}$ = $\frac{1}{F }$

                          ⇒          v = $F_{}$

Hence this diagram is correct.

(III) In this diagram:

u= - F , f = F, v is to be calculated.  (negative sign of u shows position behind lens)

Substituting values in (1),

                                      ⇒  $\frac{1}{v}$ - (-$\frac{1}{F}$) = $\frac{1}{F}$

                                      ⇒  $\frac{1}{v}$ + $\frac{1}{F}$ = $\frac{1}{F}$

                                      ⇒ $\frac{1}{v}$ = 0                          

                                      ⇒ v = ∞                       (reciprocal of 0=∞)

Hence option (III) is also correct.

(IV) In this diagram the object is placed at focus of lens and is shown to converge back at the focus on the other side. This has already been proved wrong as per option (III)

Hence the correct option is (c) I,II and III.