1. The existence of a magnetic field around a current-carrying conductor can be demonstrated by placing the conductor near a .

2. A magnetic field will be produced by moving .

3. The field around a permanent magnet is caused by the motions of spinning .

4. If an iron core is removed from a solenoid, the magnetic field strength of the solenoid will .

5. The maximum potential difference will be induced across the wire when the angle between the direction of the motion of the wire and the direction of the magnetic field is .