Question

Fig., shows a horizontal solenoid connected to a battery and a switch . A copper ring is placed on a friction track,the axis of the ring being along the axis of the solenoid. As the switch is closed, the ring will

• A. remain stationer
• B. move towards the solenoid
• C. move away from the solenoid
• D. move towards the solenoid or away from it depending on which terminal (positive or negative) of the battery it connected to the left end the solenoid

Answer 1

The correct option is C move away from the solenoid

Whatever the polarity of the solenoid end be the $flux$ will get increse from $zero$ to some value so according to

$Len{z}^{\prime }s$ law the induced current in the $ring$ will $oppose$ the $change$ that is the $increase$

so the ring will move $away$ from the solenoid to $decrease$ the flux.