Question

3. Which of the following materials is generally
used as the core of an electromagnet?
(a) Steel
(b) Iron
(c) Alnico
(d) Magnetite
4. Which of the following is not true of magnetic
lines of force?
(a) They do not intersect each other.
(b) They are continuous curves.
(c) They are crowded together where the magnetic field is weak.
(d) They go from the north pole to the south
pole outside a magnet and from the south pole to the north pole inside it.​

Answer 1

3. Which of the following materials is generally used as the core of an electromagnet?

(a) Steel

(b) Iron ✔✔

(c) Alnico

(d) Magnetite

4. Which of the following is not true of magnetic lines of force?

(a) They do not intersect each other.

(b) They are continuous curves.

(c) They are crowded together where the magnetic field is weak. ✔✔

(d) They go from the north pole to the south pole outside a magnet and from the south pole to the north pole inside it

Answer 2

Answer:

1. In electromagnets we Generally use Soft iron core

Explanation:

as it remove all its magnetism when current is cut off.

2. In question 2

option c is wrong as we know that near poles of magnet magnetic field lines are very Close due due which magnetic field is very strong there

hence when magnetic field lines crowd when there is strong magnetic field.

.

. Mark it.