It is a stretch of the atmosphere ranging from the upper mesosphere to the lower parts of the thermosphere. It’s useful to us in radio communication.
        
                    
             
        
        
        
Drag Force = bv^2 = ma; a = g = 9.81 m/s^2
b = mg/v^2 = (0.0023×9.81)/(9.4^2)
b = 0.000255
        
             
        
        
        
Answer:
Given:
radius of the coil, R = 6 cm = 0.06 m
current in the coil, I = 2.65 A
Magnetic field at the center, B =  
 
Solution:
To find the number of turns, N, we use the given formula:

Therefore,

 
 
N = 22.74 = 23 turns (approx)
  
 
        
             
        
        
        
Magnetism is the product of a moving charged particle. We can have electricity without magnetism but we can not have magnetism without electricity.An electro magnet is made so that we have a soft metal core and electricity around it. A bar magnet is a normal magnet in bar shape with permanent magnetism.