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Several Multiple choice questions regarding magnetic fields.

13. Resistors in series have a total resistance
a. greater than any individual resistor
b. smaller that any one individual resistor
c. smaller than if they were all wired parallel to each other
d. none of these
14. ____ magnetic poles attract, and _____ magnetic poles repel.
a. like, opposite
b. opposite, opposite
c. like, like
d. opposite, like
15. A magnetic field is represented by a group of exes on the page, with an arrow to the right representing the velocity of a proton. How would the force exerted by the magnetic field be shows?
a. an arrow pointing to the bottom of the page
b. an arrow pointing to the top of the page
c. a bunch of dots on the page
d. an arrow pointing to the left
16. The earth has a magnetic field because of
a. of convection currents in the outer iron core
b. little magnetism elves work day and night aligning the magnetic domains
c. the electrons of all the elements in the earth spin the same direction
d. gravity
17. As the number of coils around an iron core increase, the magnetic field
a. strength increases
b. strength stays the same
c. strength decreases

Solution Preview

<br>13. The equivalent resistance of Resistors in series is the sum of all the resistors. Resistance is positive number, thus the equivalent resistance is larger than any individual resistor.
<br>Like with electric charges, opposites attract and similar repel.
<br>15. the Lentz' force ...