SUUDVA
3. a) What is a magnetic field?
b) State two methods of making magnets
4. a) Distinguish between permanent magnets
and temporary magnets.
b) i) What are electromagnets?
ii) State three uses of electromagnets
in everyday life.
c) State three way methods of making a
magnet.

3. The magnetic field is the area around a magnet in which there is magnetic force.

(1) Single touch method (2) Double touch method (3) Using electric current.

4. The difference between a permanent magnet and a temporary magnet is in their atomic structures. Permanent magnets have their atoms aligned all the time. Temporary magnets have their atoms aligned only while under the influence of a strong external magnetic field.

Electromagnets are temporary and artificial magnets. They are magnets that are only magnetic when there is a coil of wire with electricity running through it.

Motors and generators, Transformers, Relays, Electric bells and buzzers, Loudspeakers and headphones, Actuators such as valves, Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks, MRI machines etc. (there is a lot)

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.