Answer:
he switch is open when the magnetic field is activated, a magnetic force is applied to the reed, which causes it to move, closing the circuit and allowing the lock to open.
Step-by-step explanation:
The reed switches, this is metallic, generally iron, in general the switch is open when the magnetic field is activated, a magnetic force is applied to the reed, which causes it to move, closing the circuit and allowing the lock to open.
The force is given by
F = i l x B
In the systems when the switch is depressed the magnetic field is created in a solenoid and this field attracts the metal of the reed.