(a) What happens when a bundle of wires of soft iron is placed inside the coil of a solenoid carrying a steady current? Name the device obtained. Why is it called so? (b) Draw the magnetic field lines inside a current carrying solenoid. What does this pattern of magnetic field lines indicate?

(a) When a bundle of wires of soft iron is placed inside the coil of a solenoid carrying a steady current, it becomes magnetised and is called an electromagnet. It is called so because it is a magnet produced by an electric current. (b) The magnetic field lines inside a current carrying solenoid are in the form of parallel straight lines. This indicates that the magnetic field is the same at all points inside the solenoid, i.e., the field is uniform inside the solenoid.