Answer:
Diameter will be 351.42 mm
Explanation:
We have given current flowing in the copper wire i = 310 A
Voltage drop across the wire V = 0.55 volt
We know that resistance is given by
Length of the copper wire l = 1 m
Resisitivity of the copper wire
We know that resistance
As area
So diameter = 351.42 mm
Answer:
, charges are both positive or both negative
Explanation:
The electrostatic force between the two spheres is given by
where
k is the Coulomb's constant
q1 and q2 are the charges on the two spheres
r is the distance between the centres of the two spheres
In this problem, we have
is the force
is the distance between the spheres
because the two spheres have identical charge
Solving the formula for q, we find
And the two charges have the same sign (so, both positive or both negative), since the sign of the force is positive (+0.30 N), so it is a repulsive force.