An object is placed at a distance of 10cm from a lens of power 4D…

power 4dThe power of a lens is +4D. Find the focal length of this lens. An object is placed at a distance of 50 cm from the optical centre of this lens. State the naturePower Workout 4D brings Fitness Information and Tips for people looking Easy Exercises and Workouts to Get in Shape and Lose Weht at Home without going to gym.