Explanation:
mass of earth (m1)=5.97×10^24
mass of moon (m2)=7.35×10^22
distance between their center (d)= 3.84×10^8
G=6.67×10^-11
now,
gravitational force =(F)= G(m1×m2)/d²
- 6.67×10^-11(5.97×10^24×7.35×10^22)/(3.84×10^8)
- 19.84×10^19
<h3>stay safe healthy and happy...</h3>

<h3>Explanation</h3>
,
where
is the current;
is the drift speed;
is the cross-section area of the wire,
is the number of charge carrier per unit volume, and
is the charge on each charge carrier.
Area of a circular cross-section:
,
where
is the radius of the wire.
and
are the same for all four samples, for they are made out of the same material.
As a result,
of each wire is directly proportional to
where the value of
is constant.
For each of the four wires:
.
How do the four wires rank by their current?
d > a > b > c.