Magnetism Quiz - ScienceScene

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18 Οκτ 2013 (πριν από 3 χρόνια και 11 μήνες)

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MAGNETISM

Quiz



Directions:

Select the best answer.






F
Force at new position

=
F
Force at source

/ (
d

Distance from source
)
2



1. 08, 1

Changes direction of current in the armature of a direct current motor:


A) transformer



B) magnet




C) commutator



D) insulators



E) hertz



2. 08, 1

A group of atoms with many of their electrons spinning in the same direction is called?


A) ferromagnetic molecules



B) domain



C) conductor




D) insulator



3. 08, 2

Which one of the following models represents a non magnetic material?




A) B) C) D)
E)




4. 08, 2

Which one of the following models represents a magnetic material?





A) B) C)

D) E)




5. 08, 3

The magnetic lines of force near a current carrying wire are:


A) straight lines parallel to the wire


B) straight lines perpendicular to the wire


C) circula
r in a plane perpendicular to, around, the wire


D) circular in a plane parallel to the wire




6. 08, 3

Magnetic fields are produced by:

A) motion of an electric charge

B) static electric charge

C) free electrons moving in magnetic fields

D) phot
on motion



7. 08, 4

A generator produces electrical current by:

A) moving a coil of copper wire through a magnetic field


B) heating water and burning it into steam which is used to make electricity

C) using fuel oil or some other source of energy

D
) rubbing a strong magnet with a wool pad

E) none of the above



8. 08, 4

One way to increase the power of a generator is to:


A) increase the north polarity of the magnetic field


B) increase the number of loops in the coil of wire


C) decrease the
free electrons moving in magnetic field


D) decrease the coil insulator



9. 08, 5

Which of the following explains why the force of a magnet decreases with distance.



A) ferromagnetism decreases with distance



B) dipoles decre
ase with distance



C) lower frequency at greater distance



D) inverse square law



E) flow of electrons decreases with distance


10. 08, 5

If a magnetic at one meter has a strength of 25 newtons what is the force at

5 meters?



A) 1 newtons



B) 2 newtons



C) 3 newtons



D) 4 newtons



E) 5 newton


11. 08, 6

Which of the following is/are needed for an electric motor to work.



A) insulator



B) coil of wire



C) magnetic declination



D) galvanometer



E) static electricity


12. 08, 6

Which of the following explains how an electric motor works.



A) reverse square law




B) flow of electrons in ferromagnetic conductors



C) switching the flow of electric current in a magnetic field


D) dipole insulators in magnetic poles with free electron movement


E) all of the above