Chapter 18, Problem 7STP

To determine

To Choose: The correct option.

Answer to Problem 7STP

Option B

Explanation of Solution

Given:

Object distance, $u=3.0\text{m}$

Focal length of the diverging lens, $f=-2.0\text{m}$

Formula used:

Lens formula:

  $\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

Here, v is the image distance, u is the object distance and fis the focal length.

Calculations:

Substitute the values:

  $\begin{array}{l}\frac{1}{v}+\frac{1}{u}=\frac{1}{f}\\ \frac{1}{v}+\frac{1}{3}=\frac{1}{-2}\\ \frac{1}{v}=\frac{1}{-2}-\frac{1}{3}\\ v=-\frac{3\times 2}{3+2}\\ v=-1.2\text{m}\end{array}$

Conclusion:

Thus, option B is correct.