Final answer:
To determine a solenoid's polarity, connect it to a battery and observe the compass needle deflection when the solenoid is energized, using the right-hand rule to confirm the polarity of magnetic poles.
Step-by-step explanation:
To identify the polarity of a solenoid using the provided materials, you can follow these steps:
- Connect the solenoid to the 3V battery using the switch and the rheostat in series to regulate the current flowing through the solenoid.
- Place the magnetic compass near the solenoid and close the switch to allow current to flow through the solenoid.
- Observe the direction in which the compass needle deflects. The end of the solenoid towards which the north end of the needle points is the magnetic south pole of the solenoid, while the opposite end is the magnetic north pole.
- Use the right-hand rule to confirm this: curl the fingers of your right hand in the direction of the current flow through the solenoid's turns, and your thumb will point towards the north pole of the solenoid.
Remember that flipping the direction of the current will also reverse the magnetic poles of the solenoid.