You will need
- vibrator Hertz
- - resonant circuit with the possibility of changing the settings,
- - copper wire,
- - iron core,
- - a set of devices for measuring magnetic and electric fields.
The determination of the frequency of the electromagnetic field Take the Hertz dipole. This is a copper rod, with balls at the ends, in the gap which is inserted a Ruhmkorff coil (two windings on one core). If you make it to the electromagnetic field, adjust the clearance of the rod, yet it does not begin to slip sparks. With reference to these parameters, find the frequency of this vibrator, it will be the frequency of the external electromagnetic field.
In the second case, take a resonant circuit with a coil of small inductance and a capacitor of large capacitance. Included in this resonant circuit the ammeter, and (by changing its parameters, for example, increasing or decreasing capacity) measure, at what values it is the most current. It will be observed from the coincidence of the natural frequency of the loop oscillation frequency of the electromagnetic field. This technique is used in radios, and therefore you can take the path with them. Devices measure the inductance of the coil and the capacitance of the capacitor in which there is resonance, then from the product of inductance and capacitance extract the square root and then multiply the result by the number of 6.28. The number 1 divide by the result of calculations. The result will be the frequency of the external electromagnetic field in Hertz.
Determination of the intensity of the electromagnetic field If it is known that at a given point of space is the electromagnetic field, take a copper wire of large cross-section with a length of about 1 m, wrap it into a solenoid (a few isolated threads) and the leads (the ends of the conductor), connect the voltmeter. An alternating magnetic field, which is a component of an electromagnetic field, excite in the conductor EMF, measure it with a voltmeter. The more indications of the voltmeter, the more intense the field. Special gauges of the magnetic field can define its intensity in different frequency bands. Make a sensor device in the field on the screen will appear the options.