$430$

$20.$ Induction

Shown at left is a small solenoid with five loops $(1)$ and a larger solenoid $(2),$ each connected to a battery. A constant current has been generated in each one. Note the orientation of the battery in each solenoid and the direction of the current around the coils of each solenoid.

a$)$ If both coils are stationary:

Is there an induced current through solenoid l$?$ If yes, indicate the direction of the induced current. Explain your reasoning.

Is solenoid $1$ attracted to or repelled by $2,$ or is there no force at all between them? Explain your reasoning.

b$)$ If solenoid $1$ is moving toward solenoid $2$:

Is there an induced current through solenoid l$?$ If yes, indicate the direction of the induced current. Explain your reasoning.

Is any force by solenoid $2$ on solenoid $1$ larger, smaller, or the same as in part $($a$)?$ Explain your reasoning.