To solve this problem it is necessary to apply the concepts related to the capacitance in the disks, the difference of the potential and the load in the disc.
The capacitance can be expressed in terms of the Area, the permeability constant and the diameter:
Where,
= Permeability constant
A = Cross-sectional Area
d = Diameter
Potential difference between the two disks,
V = Ed
Where,
E = Electric field
d = diameter
Q = Charge on the disk equal to 
Through the value found and the expression given for capacitance and potential, we can define the electric charge as
Re-arranging the equation to find the diameter of the disks, the equation will be:
Replacing,
Therefore the diameter of the disks is 0.03m
Answer:
light doesn't need a medium through which to travel because the speed of light is experimentally constant
In an Internal Combustion Engine, the fuel is singed in the chamber or vessel. Example: Diesel or Petrol motor utilized as a part of Cars.
The internal engine has its vitality touched off in the barrel, as 99.9% of motors today. In an External Combustion Engine, the inner working fuel is not consumed. Here the liquid is being warmed from an outer source. The fuel is warmed and extended through the interior instrument of the motor bringing about work. Eg. Steam Turbine, Steam motor Trains. An outer burning case is a steam motor where the warming procedure is done in a kettle outside the motor.
