A student wrapped 30 cm of an insulated wire around the middle of an iron rod, leaving ends A and B exposed. She connected the non-insulated ends of the wire to a battery. She brought a permanent magnet near end B of the iron rod, and it was repelled. The picture shows the student's experiment.Which best explains why the permanent magnet was repelled?A The wire became magnetized when an electric current flowed through it, and end B of the iron rod must have shared the same pole with the permanent magnet.B The iron rod became magnetized when it was wrapped by the wire, and end B of the iron rod must have had a pole opposite that of the permanent magnet.C The iron rod became magnetized when it was wrapped by the wire, and end B of the iron rod must have shared the same pole as the permanent magnet.D The wire became magnetized when an electric current flowed through it, and end B must have had a pole opposite that of the permanent magnet.

A coil of wire is carrying an electric current. How will the magnetic field of the coil be affected if an iron rod is placed in its center ?A The field will be cancelled out. B The strength of the field will increase. C The strength of the field will decrease. D The direction of the field will reverse.

Which of the following statements about permanent magnets is incorrect?They produce their own magnetic fields and always have a north pole and a south poleThe force between two permanent magnets will increase when they are brought closer to one anotherThey can be attracted to or repelled by other permanent magnetsUnder certain circumstances, they will only be attracted to other permanent magnets5An iron nail is initially unmagnetised.  Which one of the following things will occur when it is brought closer to the north pole of a permanent bar magnet?Nothing will happen since the iron nail is not a permanent magnetThe iron nail will be repelled by the bar magnetThe iron nail will be permanently magnetisedThe end of the nail which is placed closest to the north pole of the bar magnet will become an induced south pole

Which of the following will prove that a metal bar is a permanent magnet?*1 pointit attracts another magnetit attracts both ends of a compass needleit conducts electricityit repels another magnet

An iron nail is initially unmagnetised.  Which one of the following things will occur when it is brought closer to the north pole of a permanent bar magnet?Nothing will happen since the iron nail is not a permanent magnetThe iron nail will be repelled by the bar magnetThe iron nail will be permanently magnetisedThe end of the nail which is placed closest to the north pole of the bar magnet will become an induced south pole

Question 17A student wraps a copper wire around a nail and then connects the wire to a battery.Which statement describes the role of the nail in this set-up?A The nail is an electromagnet. The current in the wire induces a magnetic field from the nail.B The nail is a permanent magnet. The current in the wire induces a magnetic field from the nail.C The nail is an electromagnet. The magnetic field from the nail induces an electric current in the wire.D The nail is a permanent magnet. The magnetic field from the nail induces an electric current in the wire.