Ahollow circular nylon pipe (see fig) supports a load pa = 1750 lb, which is uniformly distributed around a cap plate at the top of the lower pipe. a second load pb is applied at the bottom. the inner and outer diameters of the upper and lower parts of the pipe are d1 = 2 in., d2 = 2.375 in., d3 = 2.25 in., and d4 = 2.5 in., respectively. the upper pipe has a length l1= 14in., the lower pipe length is l2 = 16 in. neglect the self-weight of the pipes. -if pa remains unchanged, find the new value of pb (in lb) so that upper and lower parts have same tensile stress.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia