Electric Bell Circuit Deactivation

Steps:

• Battery P powers the circuit, energizing the electromagnet and attracting the iron armature to strike the bell.
• Disconnecting battery P breaks the circuit, stopping current flow to the electromagnet.
• Without current, the electromagnet loses its magnetic field.
• The iron armature, no longer attracted, falls back due to gravity or spring force, halting the bell's vibration.

Why A is correct:

• Disconnection stops current per Ohm's law (I = V/R), de-energizing the electromagnet and allowing the armature to fall, ending ringing as defined in electromagnetic induction principles.

Why the others are wrong:

• B: Armature falls, not moves up, without magnetic attraction.
• C: Armature falls and bell stops, not the reverse.
• D: Armature falls, not moves up, upon de-energization.

Final answer: A