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WorksheetsMagnetic Fields and Induction
Total questions: 28
Worksheet time: 21mins
Can you produce current in a wire with a magnet that is sitting still?
Yes; having a magnet near a wire is enough to excite the electrons
No; the magnetic field has to be changing to excite the electrons
No; magnets cannot create electricity
A coil spins in a magnetic field. Of the following which causes an increase in the induced EMF in the coil?
Spinning the coil faster
Removing the coil from the magnetic field
Keeping the flux at a constant rate
Decreasing the number of turns of wire in
the coil
According to Faraday's Law, in which of the following scenarios would you expect to generate an electrical current in a loop of wire?
a. Moving the loop near a stationary magnet.
b. Moving a magnet near the stationary loop.
c. Changing the current in a nearby wire.
d. All of these
What would happen if I move a bar magnet in and out of a coil of copper wire, demonstrating Faraday's Law?
Electric current would disappear
The magnet would explode
Electric current will flow through the wire
It would produce a gravitational field
According to Lenz's Law, in which direction is the magnetic field induced when a conductor moves through a magnetic field?
Left
Right
Up
Down
Magnetic flux is related to magnetic field strength by the formula
Φ=BA
Φ=BA2
Φ=B/A
Φ=B/A2
When a charged particle moving with velocity v enters a magnetic field at right angles it will be forced into a circular path with radius r given by
mv/Bq
Bq/mv
mv2/Bq
none of these
The size of the force exerted on a moving charge relative to an external magnetic field is given by
Bqv
Bqvcosθ
Bqvsinθ
none of these
A uniform magnetic field of strength 4 mT is used to deflect a beam of electrons into a circular path of diameter 65 mm. Calculate the speed of the electrons
2.3x107ms-1
4.6x107ms-1
3.0x107ms-1
2.0x107ms-1
What does the direction of the pointing fingers mean in this picture?
the direction of the voltage
the rotation of the wire
the direction of the magnetic field
the direction of the current
F = BIL If the current and magnetic field are doubled, the magnetic force on the wire
halves
remains the same
doubles
quadruples
F = qvB If the speed and charge double, what happens to the magnetic force?
halves
remains the same
doubles
quadruples
The magnetic field oriented into the page has an initial field strength of 5 Tesla into the page. It changes to 2 Tesla into the page. What is the direction of the induced current?
CW
CCW
Magnetic flux is measured in
teslas
volts
webers
volts/s
A conductive loop moves downward into the magnetic field as shown in the diagram. Which way will the induced current flow in the conductive loop?
CW
CCW
Can you produce current in a wire with a magnet that is sitting still?
Yes; having a magnet near a wire is enough to excite the electrons
No; the magnetic field has to be changing to excite the electrons
No; magnets cannot create electricity
The magnetic field oriented out of the page has an initial strength of 6 Tesla. Over time the field out of the page increases to 10 Tesla out of the page. What is the direction of induced current in the loop?
CW
CCW
A conductive loop moves upward out of the magnetic field as shown in the diagram. Which way will the induced current flow in the conductive loop?
CW
CCW
A wire carries a current, creating a magnetic field around itself as shown. The current in the wire is:
Directed to the right
Directed to the left
Equal to the magnetic field
In the same direction as the magnetic field
The magnetic field oriented out of the page has an initial strength of 7 Tesla. Over time the field out of the page decreases to 2 Tesla out of the page. What is the direction of induced current in the loop?
CW
CCW
