An object is kept at a distance of 100 cm from lens of power - 4 D

power 4dPower 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.Two lenses have power of (i) + 2 d (ii) -4D. What is the nature and focal length of each lens? b. An object is kept at a distance of 100 cm from lens of power -4D. Calculate the image distance.