Why are the two-source interference equations not valid for an observer on a road far away from two neighboring radio towers for different radio stations? sources emit at different frequencies (i.e., not monochromatic sources) incoherent sources observed from a distance similar to or smaller than the separation between the sources 1 only 2 only 3 only 1 and 2 only 1 and 3 only 2 and 3 only all three Request Answer Part D Why are the two-source interference equations not valid for light from an incandescent bulb that passes through a screen with two narrow slits onto an observation screen directly behind it? not monochromatic sources incoherent sources observed from a distance similar to or smaller than the separation between the sources 1 only 2 only 3 only 1 and 2 only 1 and 3 only 2 and 3 only all three Request Answer Part E Consider a road that runs parallel to the line connecting a pair of radio towers that transmit the same station (assume that their transmissions are synchronized), which has an AM frequency of 1000 kilohertz. If the road is 5 kilometers from the towers and the towers are separated by 400 meters, find the angle to the first point of minimum signal ( m=0 ). Hint: A frequency of 1000 kilohertz corresponds to a wavelength of 300 meters for radio waves. Express your answer in radians, to two significant figures. Activate to select the appropriates template from the following choices. Oper