A solenoid has a radius of 1.85 cm and 1110 turns per meter. Over a certain time interval the current varies with time according to the expression I = 2.50t, where I is in amperes and t is in seconds. Calculate the electric field 5.47 cm from the axis of the solenoid...
The Earth's radius is 6370 km . There is a downward-pointing electric field in the atmosphere above the Earth's surface, of average magnitude 140. N/C .
a) What is the flux of the electric field out of the Earth?
b) What is the charge on the Earth?