Download 11 - The Left Hand RULES!!!

3/15/2012
P30 Unit B: Forces and Fields
The Left Hand RULES!
Name: _________
Date: _________
1. The diagrams below show a compass at various positions around a current carrying wire.
Draw the direction the compass needle would point in each diagram.
⃑ -field
2. In the diagram below left, given the direction of the current, draw the direction of the 𝐵
at A, B and C.
3. Using the diagram above right, fill in the blanks with the letter/word that makes the sentence
true.
⃑ -field due to the magnets is from letter ___ to ___.
a) The direction of the 𝐵
⃑ -field due to the wire is _______________.
b) If current flows from E to F, the direction of the 𝐵
(clockwise/counterclockwise)
c) If current flows from E to F, the direction of the magnetic force on the wire is towards letter
___.
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3/15/2012
4. In the diagram below, current is moving through a wire into the plane of the page. Draw the
direction of the magnetic force acting on the wire.
⃑ -field produced by an electron travelling
5. The diagram below left shows the direction of the 𝐵
through space. Draw in the direction of the electron’s velocity.
⃑6. The diagram above right shows a conducting wire traveling through a region containing a 𝐵
field. Draw in the direction of current flow induced through the wire.
⃑ -field. Draw in i) the path of the
7. The diagram below left shows an electron entering a 𝐵
electron ii) the direction of the magnetic force acting on the electron in four different positions
and iii) the direction of the velocity of the electron in four different positions.
⃑ -field between two bar
8. In the diagram above right a positive aluminum ion enters the 𝐵
magnets. Which letter, X or Y, will the ion move towards?
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3/15/2012
9. The diagram below left shows the top half of a current carrying wire loop moving through a
⃑ -fields around the loop of wire and through the
piece of cardboard. Draw in the direction of the 𝐵
centre of the loop.
10. The diagram above right shows a circuit for a lifting electromagnet. Label the poles of each
electromagnet when the switch is closed.
⃑ -field. Draw in the
11. The diagram below left shows a current carrying wire moving through a 𝐵
direction of the magnetic force acting
on the wire.
12. The diagram above right shows a loud speaker. The speaker consists of several parts: a strong
permanent magnet in the shape of a letter “E” with two south poles at the top and bottom and a
north pole in the middle, as shown, and a voice coil attached to the paper speaker cone. The
voice coil is a coil of conducting wire with a current passing through it as shown. The voice coil
and cone are free to move towards or away from the magnet.
Draw in the direction of the force acting on the voice coil and cone below.
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3/15/2012
13. The diagram below shows a positive particle entering a region of perpendicular electric and
magnetic fields. The electric field is produced by the two parallel plates as shown. Ignoring the
force of gravity, if the particle is to travel through the fields undeflected:
a) Draw in the direction of the electric and magnetic forces acting on the particle.
b) Label the plates as either positive or negative.
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