Answer:
d) 1/4 F
Explanation:
The magnitude of electrostatic force between stationary charges is described by Coulomb's law. This law states that this force is proportional to the magnitudes of the charges:
When each of the spheres has lost half its initial charge, we have:
So, the new electrostatic force is:
Answer:
0.0389 cm
Explanation:
The current density in a conductive wire is given by
where
I is the current
A is the cross-sectional area of the wire
In this problem, we know that:
- The fuse melts when the current density reaches a value of
- The maximum limit of the current in the wire must be
I = 0.62 A
Therefore, we can find the cross-sectional area that the wire should have:
We know that the cross-sectional area can be written as
where d is the diameter of the wire.
Re-arranging the equation, we find the diameter of the wire: