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A
charge of is traveling with a velocity of enters an unknown magnetic field. The charge experiences a magnetic force of . What is the magnitude and direction of the
unknown magnetic field? |
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We know we have to resolve the cross
product to determine the direction, so we need to be the result of a vector crossed with since that is the result, so from the right
hand rule would give up if we had but we have a minus sign from the charge we
need to deal with so reverse and make it .
Then we have which is what we need. Therefore, we know B points in the
East! Now we can do the math to get the
value of B |
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So Correct Answer is D ! |
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An
object has a mass and a charge and is traveling with a speed in a direction, which makes a angle with a magnetic field of strength . This results in the mass traveling in a
circle, which has a radius . How much work does the magnetic field do if
the mass makes 3.0 revolutions around the circle? |
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Since the force created by the
magnetic field is a centripetal one and points towards the center of the
circle along a radius, and the speed will be tangent to the circle, the force
is perpendicular to the displacement of the mass and no work is done by the
magnetic field! |
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So Correct Answer is A ! |
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An
object has a charge . It is traveling with a velocity . It encounters a magnetic field described by
. What is the resulting magnetic force acting
on the object? |
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Since velocity is in the direction and the magnetic field is in the the
result of the cross product is |
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So Correct Answer is C ! |
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An
ion has lost two electrons so it is charged to +2e. It has a mass . It is making a circle of radius in a magnetic field strength , which is
directed into the plane the ion is making the horizontal circles in as shown
below. What is the speed with which
the ion is moving around the circle and is it going clockwise or counter
clockwise in its orbit? |
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The Magnetic Force is the
Centripetal Force so |
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Solving for |
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For a positive charge, the force
will be directed towards the center of the circle if on the right side of the
circle we have the velocity going up then when crossed into B field going
into the paper, we get a force going towards the center. Therefore, if v is going up on the right
side, we must be going counter-clock-wise!
So answer is |
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So the Correct Answer is A ! |
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The
source that creates a magnetic field in space is best described by? |
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So Correct answer is C ! |
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