Young double slit arrangement is placed in a liquid medium of 1.2 refractive index. Distance between the slits and screen is 2.4 m.
Slit separation is 1 mm. The wavelength of incident light is 5893 Å. The fringe width is:
Find the least horizontal force \( P \) to start motion of any part of the system of three blocks resting upon one another as shown in the figure. The weights of blocks are \( A = 300 \, {N}, B = 100 \, {N}, C = 200 \, {N} \). The coefficient of friction between \( A \) and \( C \) is 0.3, between \( B \) and \( C \) is 0.2 and between \( C \) and the ground is 0.1.