Magnet 4
A proton (charge +e) sits at rest in a
uniform magnetic field, B, that points to the
right. What is the direction of the force on
the charge?
+e
A:
B: 0 (no force)
C:(into the page)
D: (out of the page)
B
Magnet 5
A neg. and a pos. particle move with certain
velocities in a constant, uniform magnetic field
(which points to the right.) The (+) particle moves
directly left; the (–) particle moves directly up.
The force on the (+)
particle due to the Bfield is…
B
+
-
A: into page
C: 0
B: out of page
D: right
E: left
Magnet 6
A neg. and a pos. particle move with certain
velocities in a constant, uniform magnetic field
(which points to the right.) The (+) particle moves
directly left; the (–) particle moves directly up.
The force on the (-)
particle due to the Bfield is…
A: into page
C: 0
B
+
B: out of page
D: right
-
E: left
Magnet 8
A + particle is released from rest in a
region where there is a constant,
uniform, E-field and a B-field (shown
below).
Which path will the positive particle
follow? (Paths shown are in plane of
page.)
E
B(out)
A B C
D: will not move
E: other
Magnet 9
What is the radius of the orbit of a particle of mass,
m, velocity, v , with charge, q in a uniform magnetic
field of magnitude, B?
A)
rorbit
qB
=
mv
B)
rorbit
m
=
qB
rorbit
mv
=
qB
2
C) rorbit
mv
=
qB
D)
E) None of the above
Magnet 10
A (+) particle with initial speed vo moves
perpendicular to a uniform magnetic field
(B into the page). There is a tenuous gas
in the region causing viscous drag. The
particle…
B
A: spirals in
B: spirals out
Magnet 11
A particle with unknown charge q moves
right with speed v. It enters a region with
uniform electric field up and uniform
magnetic field out of the page It goes in a
straight line.
The sign of q must be…
A: + B: C: 0
D: impossible to
determine
E
v
B
Magnet 12
Suppose the particle in the last question
is a proton. If the speed of the proton is
increased, it will
A: still undergo no deflection
B: deflect out of the plane of the page
C: stay in the plane of the page and
deflect upward
D: stay in the plane of the page and
deflect downward
E: None of these