Page 121 - Physics_Form_2
P. 121
Magnetism
Exercise 3.3 around both. Compare the magnetic
1. A student wants to turn an iron nail field patterns of the two magnets.
into a temporary magnet to pick up 7. A student claims that magnetic field
small pins. What should the student strength is the same all around a bar
do to magnetise the nail, and how magnet. Do you agree or disagree?
FOR ONLINE READING ONLY
will the student know it has become Justify your answer.
magnetic?
2. Two students tried to magnetise two Earth’s magnetic field
similar iron nails. Student A used The Earth behaves as if it has a short bar
the stroking method, and Student magnet inside it (See Figure 3.44). This
B placed the nail inside a solenoid apparent magnet is inclined at a small
and passed an electric current. angle to the Earth’s axis of rotation, with
Later, Student A’s magnet picked up its south pole pointing in the northern
fewer paper clips than Student B’s. hemisphere. This is inferred from the fact
Describe the methods used. Why that the compass needle points towards
were the results different? the true north only at certain locations.
3. A technician suggests heating a
magnet to make it stronger. Do you
agree or disagree? Give reasons.
4. Suppose you are helping in designing
a magnetic tool for lifting nails in
a workshop. However, the magnet
gets demagnetised frequently due
to rough handling. Propose an
improved design or method that
ensures the tool stays magnetised
for a longer time, and explain why
your design would work better.
5. A student places a bar magnet under Figure 3.44: Earth’s imaginary magnet
a sheet of paper and sprinkles iron The source of the Earth’s magnetism
filings on top. What pattern will the remains uncertain and lacks a
filings form, and what does this show straightforward explanation. However,
about the magnetic field? it is believed that the generation of the
6. Two magnets, one bar magnet and magnetic field is linked to the rotation of
the Earth. This leads to the rotation of the
the other a horseshoe magnet, are metallic iron fluid that makes up a large
placed on a table. A student uses portion of the interior of the Earth. The
a compass to trace the field lines Earth has two sets of poles, the north
115
Physics Form 2 Final.indd 115 25/10/2025 10:27
