Which of the following statements are correct ?

(i) An electromagnet produces a permanent magnetic field.

(ii) An electromagnet can produce a strong magnetic field.

(iii) The polarity of electromagnet can be reversed by reversing the direction of current in the solenoid.

1. all of the above
2. (i) and (ii)
3. (ii) and (iii)
4. (i) and (iii)

A soft iron piece is in the form of a closed ring (no free ends). A wire is wound over it to make it an electromagnet. What happens when current is passed in the wire ?

1. It does not get magnetised.
2. It gets temporarily magnetised.
3. It becomes magnetised.
4. It can be magnetised if broken into two parts.

The magnetic polarity at the two ends of a horse-shoe magnet depends on :

1. the strength of current in the coil
2. the number of turns in the coil
3. the material on which the coil is wound
4. the direction of current at the ends of the magnet.

The figure depicting the correct magnetic field lines when the magnet is placed with its south pole pointing towards north is :

1.

2.

3.

4.