Astep-down transformer is used for recharging the batteries of portable electronic devices. the turns ratio n2/n1 for a particular transformer used in a dvd player is 1: 13. when used with 120-v (rms) household service, the transformer draws an rms current of 20.0 ma from the house outlet. find
(a) the rms output voltage of the transformer and
(b) the power delivered to the dvd player.

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)