The resistivity of a semiconductor can be modified by adding different amounts of impurities. A rod of semi-conducting material of length L and cross-sectional area A lies along the x-axis between x = 0 and x = L. The material obeys Ohm’s law, and its resistivity varies along the rod according to rho(x)=rho0exp(−x/L). The end of the rod at x = 0 is at a potential V0 greater than the end at x = L. (a) Find the total resistance of the rod and the current in the rod. (b) Find the electric-field magnitude E(x) in the rod as a function of x. (c) Find the electric potential V(x) in the rod as a function of x. (d) Graph the functions rho(x), E(x), and V(x) for values of x between x = 0 and x = L.

are their multiple choices ?

explanation:

hypothesising or postulating

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

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