Transcript The unit of the magnetic field B (the Tesla) A] is the same as the

The unit of the magnetic field B (the Tesla)
A] is the same as the electric field times a velocity
B] is the same as the electric field divided by a velocity
C] cannot be expressed as either of these
(The electric field is V/m.)
What is the sign of the charge carriers in this conductor?
A] +
B] C] Can’t tell
What is the drift velocity of the negative charge carriers?
A] 0
B] 10-3 m/s
C] 10-2 m/s
D] 10-1 m/s
E] 1 m/s
A proton (+) and an electron (-)
move side by side both with
velocity v as shown.
What is the direction of the magnetic field at the electron
due to the proton (in our “laboratory” frame of reference)?
A] into page
B] out of page
C] upward
D] downward
E] to the right
A proton (+) and an electron (-)
move side by side both with
velocity v as shown.
The magnetic field is into the page, by RHR. What is the
direction of the magnetic force on the e- ?
A] into page
B] out of page
C] upward
D] to the left
E] to the right
A proton (+) and an electron (-)
move side by side both with
velocity v as shown.
The magnetic force on the electron is away from the proton.
What direction is the total (electric + magnetic) force on the
electron? (v<c)
A] into page
B] out of page
C] upward
D] to the left
E] to the right
A proton (+) and an electron (-)
move side by side both with
velocity v as shown.
The total force on the electron is still attractive, but weaker
than if no magnetic force were present.
What is the total force on the electron if v=c?
A] 0
B] infinite, away from the proton
C] infinite, toward the proton
A proton (+) and an electron (-)
move side by side both with
velocity v as shown.
The total force on the electron is still attractive, but weaker
than if no magnetic force were present.
What is the total force on the electron if v=c? Ans 0!
Clocks slow to a STOP as v -> c!
What is the contribution of the straight
sections of the wire to the magnetic field in
the center of the semicircle?
A] Each contributes 0


B] They both have contributions that are
opposite, and so add to 0
C] Each contributes
0 I
2R
D] infinite




Point P is a perpendicular distance x from each wire.
Both wires carry current I in the direction shown.
What is the magnetic field at P?
A] 0
0 I
B]
2x
0 I
C]
x
D] Insufficient information