# Problems about magnet moving back n forth inside da solenoid

Discussion in 'Electronic Basics' started by jamezun, Nov 2, 2005.

1. ### jamezunGuest

I got a coil and a rod magnet is moved back and forth. In order t
obtain the greatest current, should the rod be as long as possible
What factors affect the ac current that will be generated? no of coi
per length, strength of magnet and? What formula should I use
And how can I keep the output voltage and out current steadily

2. ### GotCoffeeGuest

e=beta*length*velocity
Beta is magnetic flux density measured in Tesla (how strong the magnet
is).
Length is the length of the conductor in the magnetic field.
Velocity is how fast the coils or magnet is moving in meters per
second.

To keep a constant voltage level, keep the magnet moving at the same
speed, preferably around in a circle like an alternator. To obtain the
greatest current, you want a strong magnet, a lot of coils and fast
movement.

Another formula to consider is:

e=(number of turns of wire)*(change in magnetic flux measured in
Webers)/(change in time)

The above formula shows that the instantaneous voltage is inversely
proportional to time.  