Question

(a) What is a solenoid? Draw a sketch to show the magnetic field pattern produced by a current-carrying solenoid.
(b) Name the type of magnet with which magnetic field pattern of a current-carrying solenoid resembles.
(c) What is the shape of field lines inside a current-carrying solenoid? What does the pattern of field lines inside a current-carrying solenoid indicate?
(d) List three ways in which the magnetic field strength of a current-carrying solenoid can be increased?
(e) What type of core should be put inside a current-carrying solenoid to make an
electromagnet?

Answer 1

The field lines within a current-carrying solenoid will be in the form of parallel straight lines. This is indicating that the magnetic field is the same at all points inside the current-carrying solenoid.

Complete Step by step answer: (a)A solenoid is a coil which is made of an insulated wire wound in the form of a cylinder usually made of solid iron, solid steel, or powdered iron which produces magnetic field when electrical phenomenon is suffered through it and behaves as a magnet.
The magnetic field pattern produced by a current-carrying solenoid is as shown in the following figure:

(b)The magnetic field pattern of a current-carrying solenoid resembles that of a bar magnet. One end of the current-carrying solenoid behaves as a magnetic north , while the other behaves as the magnetic south just like in the bar magnet.
(c)The magnetic field lines inside a current-carrying solenoid are in the form of parallel straight lines. This pattern of field lines is indicating that the strength of the magnetic field is the same at all the points inside the current-carrying solenoid. That is, the field is uniform inside the current-carrying solenoid.
(d)The strength of the magnetic field around a current-carrying solenoid can be increased by the following three ways:
-By increasing the number of turns in the solenoid,
-By increasing the current flowing through the solenoid,
-By using soft iron as core in the solenoid.
(e)Soft iron core should be inserted in a current-carrying solenoid to make an electromagnet as it increases the strength of the magnetic field and it does not retain its magnetism when the current is switched off; in other words, it does not become permanently magnetized.

Note: Candidates usually get confused while assigning the north and south pole of the solenoid. It should always be remembered that the magnetic field lines inside a current-carrying solenoid are always in the form of parallel straight lines.