Transcript Ans.

Magnetism
Challenge
If an iron bar is placed in a
magnetic field, which one of the
figures represents the distortion of
the field?
Ans. a
What is the strength of the B-field
at point P?
Ans. 4.8 x 10-5 T
What is the direction of the B-field
at point P?
Ans. Out of
screen
Electrons flow along a wire
directed out of the page. What is
the direction of the magnetic
force on the wire?
Ans. down
What is the magnitude of the B-field
at point P, if the current is 1 A?
Ans. 5 x 10-6 T
Which diagram shows the correct
magnetic field around the wire?
Ans. A (careful it
is showing
electron flow)
Which one is the correct
representation?
Ans. A
Which one is correct?
Ans. C
When the switches are closed will
these two bars attract or repel?
Ans. attract
Which is correct?
Ans. B and D
What is the correct
polarity on the
paper clips?
Ans. D
Where is the North pole?
Ans. C (ignore current arrows – look at +, - to
determine current flow)
What is the direction of the
magnetic field at the center of the
loop?
Ans. Into
screen
Where is the South pole?
Ans. D
What happens to the strength of
the field if the resistance
decreases?
Ans.
strengthens
What is the resistance? Where is
the North pole?
Ans. 8 ; D
What is the direction of the
magnetic force on the segment
AB?
Ans. Out of
screen
What is
the
direction
of
electron
flow in
the wire?
Ans. Down wire
from B to A
What is the direction of the
current in the coil?
Ans. Down
in front
Where is the field strongest?
Ans. C
What is the pole at K?
Ans. N
What is the force on segment bc?
(magnitude and direction)
Ans. 0.03 Newtons (assume 1 A
current); directed into screen
If this wire were made from a
loose chain, would it expand to
form a circle, compact to a point,
or nothing?
Ans. compact
Which shows the correct electric
field around a negative charge?
Ans. D
Which is correct?
Ans. C
Which shows the correct magnetic
field around a positive current
moving into the board?
Ans. A