Q57. One of the slit-width in Young's double -slit experiment is double the other. If the amplitude of the light wave is proportional to slit-width, then the ratio of the maximum and minimum intensity in the interference pattern is
(a) 3 : 1 (b) 6 : 1
(c) 9 : 1 (d) 12 : 1
Q58. The focal lengths of the objective and the eyepiece of a microscope are 2cm and 7cm respectively. The separation between the lenses is 20cm. At what distance from the objective should the object be placed to get the image at a distance of 25 cm from the eyepiece?
