NDA 2025
- Exam
- NDA
- Year
- 2025
- Subject
- General Ability
- Chapter
- General Science
NDA 2025 · General Ability · General Science
An object is placed between infinity and the pole (P) of a convex...
An object is placed between infinity and the pole (P) of a convex mirror. The position of the image is
Options
- Abetween pole (P) and the focus (F), behind the mirror
- Bbetween the focus (F) and infinity, behind the mirror
- Cbetween the pole (P) and the infinity, in front of the mirror
- Dat the focus (F), behind the mirror
Correct answer
A. between pole (P) and the focus (F), behind the mirror
Step-by-step solution
Using the mirror formula:
For a convex mirror, the focal length is positive (). The object is placed in front of the mirror, so the object distance is negative ().
Since and , the term is positive. Therefore, is the sum of two positive quantities, which means .
This implies that . Also, since , we have .
Thus, . The image is formed between the pole (P) and the focus (F), behind the mirror.
Answer: between pole (P) and the focus (F), behind the mirror
For a convex mirror, the focal length is positive (). The object is placed in front of the mirror, so the object distance is negative ().
Since and , the term is positive. Therefore, is the sum of two positive quantities, which means .
This implies that . Also, since , we have .
Thus, . The image is formed between the pole (P) and the focus (F), behind the mirror.
Answer: between pole (P) and the focus (F), behind the mirror