Extra question 2 A headlight (see figure below) runs on three 1.5V AAA alkaline batteries. It is specified to give 0.25 lux at 2 m and can last for 75 hours. You are wearing the headlight and reading a map. .Calculate the illuminance (in lux) on a map located 50 cm away from your head, where the angle between the normal of the map and the direction of light is 20. . Calculate the luminous flux (in lumen) of the headlight if the light is projected uniformly in a cone with an angle between the sides of 160. See diagram below. .Determine the luminous efficacy of the lamp (in Im/W) if a typical AAA alkaline battery has a capacity of 1 Ah. If you were designing the headlight, which type of light bulb will you use and why? 160