Lenz's Law In Action?

📌 CONCEPT: Lenz's Law states that the direction of the induced current in a coil is such that it opposes the change in the magnetic field that causes the current to flow.

📐 RULE / FORMULA: According to Lenz's Law, the direction of the induced current is opposite to the direction of the change in the magnetic field. This can be determined by the right-hand rule, where the fingers of the right hand are curled in the direction of the induced current, and the thumb indicates the direction of the change in the magnetic field.

💡 WORKED EXAMPLE: Suppose a bar magnet is moved towards a coil of wire, causing the magnetic field to increase. If the induced current in the coil flows clockwise, the direction of the current will be such that it opposes the increase in the magnetic field. By the right-hand rule, if the fingers are curled in the clockwise direction, the thumb will indicate the direction of the change in the magnetic field, which is towards the magnet. Therefore, the induced current will flow in the counterclockwise direction to oppose the increase in the magnetic field.

⚠️ COMMON MISTAKE: Students often get Lenz's Law confused with the right-hand rule, which only determines the direction of the induced current, not the change in the magnetic field.