Q94 / 100 · BITSAT 2022 · Physics
A mosquito $O$ is sitting infront of a glass rod having spherical end of radius of curvature $40 \mathrm{~cm}$. The image would be formed at
- Correct answerA$40 \mathrm{~cm}$ left
- Binfinity
- C$20 \mathrm{~cm}$ to the right
- D$15 \mathrm{~cm}$ to the left
Solution
As, we know, $\frac{\mu_2}{v}-\frac{\mu_1}{u}=\frac{\mu_2-\mu_1}{R}$
$$
\begin{aligned}
& \Rightarrow \quad \frac{1.5}{v}-\frac{1}{(-20)}=\frac{1.5-1}{+40} \\
& v=-40 \mathrm{~cm} \\
&
\end{aligned}
$$
Negative sign shows that image is obtained on the same side of object i.e., towards left.
Hence, the correct answer is option: 'A'.