Magnetic field is generated by moving charges, that is electric current. And generally it is equal to the work of inductance on a current square divided into 2 (W=LI²/2). Therefore to change energy of magnetic field of the conductor, change current in chains or inductance of the conductor.
It is required to you
- ampermeter, ruler, rheostat, wire, solenoid, inductance coil.
Instruction
1. Change of magnetic field you katushkisoberit the chain consisting of the coil with the known inductance which generates magnetic field, the ampermeter and a rheostat. Connect a chain to a current source. Moving the slider of a rheostat, increase or reduce current in the coil. Respectively, energy of magnetic field, and in square dependence will decrease or increase. That is increase in current by 3 times will lead to increase in energy of magnetic field by 9 times.
2. To reduce inductance of the coil, wind off a part of a wire, having reduced quantity of rounds on it. The quantity of rounds are less, the less there will be an energy of electric field and vice versa, with increase in quantity of rounds the energy will increase.
3. One more way: having kept quantity of rounds, rewind the coil on the core of other section. How much cross-sectional area will change, in so many time to change also the inductance of the coil.
4. To increase inductance of the coil, put in it the core from the environment raised by magnetic permeability. How much this size will increase, in so many time the energy of magnetic field will increase. For this purpose perfectly the iron core will approach.
5. Change of magnetic field a solenoidaizmeneniye of magnetic field of the solenoid, depending on current, same, as well as the ordinary coil. For change of inductance measure by a ruler its length and diameter. Knowing diameter, calculate the area of its cross section, having increased diameter square by 3.14 and having divided into 4. Count quantity of rounds and divide this number into solenoid length, having received quantity of rounds per unit length.
6. To change inductance of the solenoid, so and energy of its magnetic field it is possible in such ways: - having changed its length n of times; - having changed the area of its cross section in n of times; - having changed quantity of rounds on unit of length n of times - receive change of inductance in n² time; - having increased magnetic permeability of the environment in n of times.