ASSESSMENT
Direction:Encircle the letter that best completes the sentence.
1.To strengthen an electromagnet,_________.
a.decrease the voltage oil c.put a non-magnetic substance in the coil
b.increase the number of turns in a coil d.limit the battery to one
2.Which is true about electromagnets?
a.they are permanent
b.they do not need a battery
c.increasing the number of coils makes the electromagnet stronger
d.increasing the battery makes the electromagnet weaker
3.You can make an electro magnet stronger by________
a.having smaller current in the wire
b.having greener current in the wire
c.having larger current in the wire
d.having water current in the wire
4.An electromagnet is_______
a.a compass with magnet that tells direction
b.a magnet made when electric charges move through a coil of wire wrapped around an iron core or center
c.a device that produces electric current from energy stored in chemicals
d.a device that can prevent an electric shock
5.An electromagnet can be made stronger by_______
a.adding more coils of wire to the iron core.
b.using a smaller battery
c.removing all the coils and iron core
d.reversing the pole of magnet
6.In increasing the strength of an electromagnet,you need to_______
a.increase the amount of current flowing in the wire
b.change the position of the battery
c.insert a wooden core inside the coil
d.decrease the number of coils of wire
7.The strength of the magnetic field og an electromagnet can be increased by_____.
a.decrease the number of dry cell/batteries
b.decrease the current
c.increase the number of dry cell/batteries
d.increas the resistance
8.If you want to lessen the power of an electromagnet,you will have to_______.
a.increase the number of batteries
b.increase the size of the iron core
c.decrease the size of the iron core
d.lessen the time in making the electromagnet
9.An electromagnet with more coils wrapped around its iron core has more capacity in attracting metals and iron than the one with less coils because__________
a.the electromagnet with more coils has a magnetic field
b.the one with more coils insulates the current of the magnet
c.it has less current in its magnetic field
d.the electromagnet with more coils provides more current to the magnetic field