Magnetic Compasses Apparently Were First Used by

Q4: An iron nail is more strongly attracted

Q5: Which force field can accelerate an electron,but

Q6: Outside a magnet,magnetic field lines are conventionally

Q7: Magnetism is due to the motion of

Q8: Superconducting electromagnets<br>A)exist now.<br>B)may be possible in the

Q10: The field surrounding every moving electron is<br>A)always

Q11: If a compass is moved from the

Q12: Compared to the huge force that attracts

Q14: Magnet A has twice the magnetic field

Q24: Like kinds of magnetic poles repel while