The radius of the sphere is r=5.15 cm=0.0515 m, and its surface is given by

So the total charge on the surface of the sphere is, using the charge density

:

The electrostatic force between the sphere and the point charge is:

where
ke is the Coulomb's constant
Q is the charge on the sphere

is the point charge
r is their separation
Re-arranging the equation, we can find the separation between the sphere and the point charge:
The answer is A. Increase
The formula is <span>Voltage = Resistance X Current
Lets say the voltage is 10 and the resistence is 5
10 = 5 x current
Current = 2
Now, lets decrease the resistence from 5 to 2
10 = 2 x Current
Current = 5
The current increases
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Pacemaker........................................................