Two copper wires have the same length, but one has twice the diameter of the other. Compared to the one that has the smaller diameter, the one that has the larger diameter has a resistance that is

Ratio of resistance of wire with larger diameter to smaller diameter is 4.

Explanation:

Resistance is defined as the property of the material/wire to oppose the flow of current through it.

Resistance (R) of the wire is determine by the relation:

R = (рL)/A

Here р is resistivity of the wire and it depends upon the material of the wire, L is length of the wire and A is the area of the wire.

Area of wire, A = π (d/2)²

Here d is diameter of the wire.

According to the question, let R₁ and R₂ be the resistance of the two copper wires, d₁ and d₂ be there diameters respectively and L and р be the length and resistivity of the two wire respectively. Since, L and р are same foe two wires.

Hence, there ratio of resistance is given by:

 =  

=

We know that d₂ = 2d₁

=   = 4

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

statement #3 on andre"s list is false.