engineering recuitment AAI ATC Junior Executive 2025 Mock Test Series Physics Optics Refraction and Reflection
A dentist uses a hand held mirror and places it at a distance of 4 cm in front of a decayed teeth to see it magnified image by four times. The focal length of this mirror is:
1
5.7 cm
2
-5.33 cm
3
2.1 cm
4
Insufficient data