<span>This statement simply implies that the 50 million tons of coal will produce the same energy output in one year as the 0.6 million barrels per day of oil. Assuming coal is more plentiful than oil, this is significant as 50 million tons is much smaller than 219 million barrels of oil.</span>
To solve this problem we will apply the concepts related to the intensity included as the power transferred per unit area, where the area is the perpendicular plane in the direction of energy propagation.
Since the propagation occurs in an area of spherical figure we will have to


Replacing with the given power of the Bulb of 100W and the radius of 2.5m we have that


The relation between intensity I and 

Here,
= Permeability constant
c = Speed of light
Rearranging for the Maximum Energy and substituting we have then,




Finally the maximum magnetic field is given as the change in the Energy per light speed, that is,



Therefore the maximum value of the magnetic field is 
- Height (h) = 10 m
- Density (ρ) = 1000 Kg/m^3
- Acceleration due to gravity (g) = 10 m/s^2
- We know, pressure in a fluid = hρg
- Therefore, the pressure exerted by a column of fresh water
- = hρg
- = (10 × 1000 × 10) Pa
- = 100000 Pa
<u>Answer</u><u>:</u>
<u>1000</u><u>0</u><u>0</u><u> </u><u>Pa</u>
Hope you could understand.
If you have any query, feel free to ask.