What Is an Induced Current?

The current generated by the closed loop in the original magnetic field to prevent the magnetic flux of the original magnetic field from changing is called the induced current.

[gn yìng diàn liú]

1831 British physicist

Just go through the closed circuit

Judgment method: use

Factors affecting size:

The speed of wire cutting;

Speed direction of wire cutting;

the strength of permanent magnets;

the number of cut wires;

Cut the effective length of the wire.

Induction electromotive force formula: According to Faraday's law of electromagnetic induction: e = BLvsin ( is the angle between B and v)

When the conductor is stationary in the magnetic field or moves parallel to the magnetic induction line, the magnetic flux does not change, so no matter how strong the magnetic field, there is no induced current in the closed loop.

The magnitude of the induced current is proportional to the sine of the magnetic induction strength B, the length of the wire L, the speed of movement v, and the angle between the direction of movement and the direction of the magnetic induction line. Increasing the magnetic induction intensity B, increasing the length L of the wire that cuts the magnetic induction line, increasing the cutting speed v, and cutting the magnetic induction line as vertically as possible ( = 90 °) can increase the induction current.

Note: In order to increase the cutting speed, theoretically, the higher the speed, the better. However, due to the large inertia of the pointer of the meter (especially a large demonstration meter), when the cutting speed is too large, the pointer does not have time to respond to the induced current displayed by the meter Instead it decreases. therefore. Care should be taken to select an appropriate cutting speed for better demonstration results.

(These conclusions can be proved by the control variable method.)