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.Given, Power of convex lens=4D. Placed at 40 cm from a wall. To Find, Distance of a candle. Solution, It is given that ,Power = 4D. Then, P = 1f. So, 4 D = 1f