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TS EAMCET · Physics · Ray Optics

The magnifications produced by a convex lens for two position of an object are 4 and 3, respectively. If the distance of separation between the two positions of the object is \(2 \mathrm{~cm}\), then the focal length of the lens is

  1. A \(20 \mathrm{~cm}\)
  2. B \(16 \mathrm{~cm}\)
  3. C \(28 \mathrm{~cm}\)
  4. D \(24 \mathrm{~cm}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(24 \mathrm{~cm}\)

Step-by-step Solution

Detailed explanation

Given, \(m_1=4\) and \(m_2=3\) Also, \(\quad u_2-u_1=2 \mathrm{~cm}\) We know that, magnification produced by a lens is given as \(m=\frac{v}{u}\) \(\Rightarrow \quad m_1=\frac{v_1}{u_1} \Rightarrow \frac{u_1}{v_1}=\frac{1}{m_1}=\frac{1}{4}\) \(\ldots(\mathrm{i})\) and…