Two 20-penny nails are wrapped with insulated wire in the shape of a solenoid. They are...

Two 20-penny nails are wrapped with insulated wire in the shape of a solenoid. They are then laid down end to end with the heads almost touching as shown in Figure Q20.16. If a battery is connected to the solenoid of each nail as shown, will the nails be attracted or will they repel each other? Explain.