Question
Download Solution PDFAn object is placed at 20 cm in front of a concave mirror and the image formed by this mirror is at 60 cm in front of the concave mirror. What is the focal length of the mirror?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCONCEPT:
- Concave mirror: The mirror in which the rays converge after falling on it is known as the concave mirror.
- Concave mirrors are also known as a converging mirror.
- The focal length of a concave mirror is negative according to the sign convention.
- Mirror Formula: The following formula is known as the mirror formula:
where f is focal length v is the distance of the image from the mirror, and u is the distance of the object from the mirror.
CALCULATION:
Given that u = -20 cm and v = -60 cm
Mirror formula
f = -60/4= -15 cm
So the correct answer is option 1.
Last updated on Jun 26, 2025
-> The Indian Coast Guard Navik GD Application Deadline has been extended. The last date to apply online is 29th June 2025.
-> A total of 260 vacancies have been released through the Coast Guard Enrolled Personnel Test (CGEPT) for the 01/2026 and 02/2026 batch.
-> Candidates can apply online from 11th to 25th June 2025.
-> Candidates who have completed their 10+2 with Maths and Physics are eligible for this post.
-> Candidates must go through the Indian Coast Guard Navik GD previous year papers.