Acube with edges exactly 2 cm long is made of material with a bulk modulus of 3.5 x 109 n/m2. when it is subjected to a pressure of 3.0 x 105 pa its volume is:

As we know by the formula of bulk modulus

now we can rearrange it as

now the final volume after pressure is applied is given as

now we know that

now plug in all data

so volume is above after pressure is applied over it

d. air pressure decreases as altitude increases.

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