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- 1. Multiple-choice2 minutes1 pt___ Law says that the Induced current is proportional to the change of magnetic fluxLenz'Faraday'sAmpere's
- 2. Multiple-choice2 minutes1 pt
Find the direction of the magnetic force.Into the screenOut of the screenRightLeft - 3. Multiple-choice2 minutes1 ptIn 1831 who discovered electromagnetic induction?Thomas EdisonNikola TeslaMichael Faraday
- 4. Multiple-choice2 minutes1 pt
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
- 5. Multiple-choice2 minutes1 pt
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
- 6. Multiple-choice2 minutes1 ptVoltage can be induced in a wire bya. moving the wire near a magnet.b. moving a magnet near the wire.c. changing the current in a nearby wire.d. all of these
- 7. Multiple-choice2 minutes1 ptWhat would happen if I move a bar magnet in and out of a coil of copper wire?Electric current would disappearThe magnet would explodeElectric current will flow through the wireIt would produce a gravitational field
- 8. Multiple-choice2 minutes1 ptA magnet can move in a coil of wire to produce electricity in which system?GeneratorMotorMagnetTransformer
- 9. Multiple-choice2 minutes1 ptWhat is the direction of the induced magnetic field?LeftRightUpDown
- 10. Multiple-choice2 minutes1 ptWhat is the direction of the induced magnetic field?LeftRightUpDown
- 11. Multiple-choice2 minutes1 ptIn what direction is the magnet moving?LeftRightUpDown
- 12. Multiple-choice2 minutes1 ptIn what direction is the magnet moving?LeftRightUpDown
- 13. Multiple-choice2 minutes1 ptA magnetic field exerts a force on a charged particle:alwaysneverif the particle is moving across the field linesif the particle is moving along the field lines
- 14. Multiple-choice2 minutes1 pt
Magnetic flux is related to magnetic field strength by the formula
Φ=BA
Φ=BA2
Φ=B/A
Φ=B/A2
- 15. Multiple-choice2 minutes1 pt
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
- 16. Multiple-choice2 minutes1 pt
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
- 17. Multiple-choice2 minutes1 pt
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
- 18. Multiple-choice2 minutes1 pt
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
- 19. Multiple-choice2 minutes1 pt
F = BIL If the current and magnetic field are doubled, the magnetic force on the wire
halves
remains the same
doubles
quadruples
- 20. Multiple-choice2 minutes1 pt
F = qvB If the speed and charge double, what happens to the magnetic force?
halves
remains the same
doubles
quadruples
