Amicrowave oven operates with sinusoidal microwaves at a frequency of 2400 mhz. the height of the oven cavity is 25 cm and the base measures 30 cm by 30 cm. assume that microwave energy is generated uniformly on the upper surface of the cavity and propagates directly downward toward the base. the base is lined with a material that completely absorbs microwave energy. the total microwave energy content of the cavity is 0.50 µj. what magnitude force does the microwave beam exert on the base of the oven? (c = 3.00 × 108 m/s, μ0 = 4π × 10-7 t ∙ m/a, ε0 = 8.85 × 10-12 c2/n ∙ m2)

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