Answer:
Part a)

Part b)



Part c)



Explanation:
Part a)
As we know that charge density is the ratio of total charge and total volume
So here the volume of the charge ball is given as



now the charge density of the ball is given as

Part b)
Now the charge enclosed by the surface is given as

at radius of 5 cm


at radius of 10 cm


at radius of 20 cm

Part c)
As we know that electric field is given as

so we have electric field at r = 5 cm


electric field at r = 10 cm


electric field at r = 20 cm


Answer:
mainline current
Explanation:
Current that flows from and back to the power supply in a parallel circuit. Fuse. A type of circuit protection device.
Electric field between the plates of parallel plate capacitor is given as

here area of plates of capacitor is given as


also the maximum field strength is given as

now we will plug in all data to find the maximum possible charge on capacitor plates


so the maximum charge that plate will hold will be given by above
Answer:
108.7 V
Explanation:
Two forces are acting on the particle:
- The external force, whose work is 
- The force of the electric field, whose work is equal to the change in electric potential energy of the charge: 
where
q is the charge
is the potential difference
The variation of kinetic energy of the charge is equal to the sum of the work done by the two forces:

and since the charge starts from rest,
, so the formula becomes

In this problem, we have
is the work done by the external force
is the charge
is the final kinetic energy
Solving the formula for
, we find
