Download P214 Topic 4 Practice Problems 1 (Bonus+5 for Exam3) Show steps

P214 Topic 4 Practice Problems
(Bonus+5 for Exam3) Show steps for points.
[Chap29]
1. A particle (q = 5.0 nC, m = 3.0 µg) moves in a region where
the magnetic field has components Bx = 2.0 mT, By = 3.0
mT, and Bz = -4.0 mT. At an instant when the speed of the
particle is 5.0 km/s and the direction of its velocity is 120°
relative to the magnetic field, what is the magnitude of the
acceleration of the particle?
[39 m/s2]
2. A 2.0-C charge moves with a velocity of (
5. The point P lies along the perpendicular bisector of the line
connecting two long straight wires S and T that are
perpendicular to the page. A set of directions A through H
is shown next to the diagram. When the two equal currents
in the wires are directed up out of the page, the direction of
the magnetic field at P is closest to the direction of
)
m/s and experiences a magnetic force of (
)
N. The x component of the magnetic field is equal to zero.
Determine the y component of the magnetic field.
[+3.0 T]
3. A straight wire is bent into the shape shown. Determine the
net magnetic force on the wire.
[A]
[Chap.30]
1. Two long parallel wires each carry a current of 5.0 A directed
to the east. The two wires are separated by 8.0 cm. What is
the magnitude of the magnetic field at a point that is 5.0 cm
from each of the wires?
[24 mT]
2. Three long wires parallel to the x axis carry currents as
shown. If I = 20 A, what is the magnitude of the magnetic field
at the origin?
[Zero]
4. An electron follows a circular path (radius = 15 cm) in a
uniform magnetic field (magnitude = 3.0 G). What is the
period of this motion?
[0.12 ms]
[19 mT]
1 P214 Topic 4 Practice Problems
3. A long straight wire carries a current of 40 A in a region
where a uniform external magnetic field has a 30-µT
magnitude and is parallel to the current. What is the
magnitude of the resultant magnetic field at a point that is
20 cm from the wire?
[50 µT]
4. If a = 2.0 cm, b = 5.0 cm, and I = 20 A, what is the
magnitude of the magnetic field at the point P?
[6.0 µT]
5. A toroid is made of 2 000 turns of wire of radius 2.00 cm
formed into a donut shape of inner radius 10.0 cm and
outer radius 14.0 cm. When a 30.0-A current is present in
the toroid, the magnetic field at a distance of 11.0 cm
from the center of the toroid is
[0.109 T]
[Chap31. Faraday’s Law]
1. A flat coil of wire consisting of 20 turns, each with an area of
50 cm2, is positioned perpendicularly to a uniform magnetic
field that increases its magnitude at a constant rate from 2.0
T to 6.0 T in 2.0 s. If the coil has a total resistance of 0.40 Ω,
what is the magnitude of the induced current?
[0.50 A]
2. A 5-turn square loop (10 cm along a side, resistance = 4.0 Ω)
is placed in a magnetic field that makes an angle of 30° with
the plane of the loop. The magnitude of this field varies
with time according to B = 0.50t2, where t is measured in s
and B in T. What is the induced current in the coil at t = 4.0
s?.
[25 mA]
3. In the arrangement shown, a conducting bar of negligible
resistance slides along horizontal, parallel, frictionless
conducting rails connected as shown to a 2.0-W resistor. A
uniform 1.5-T magnetic field is perpendicular to the plane
of the paper. If L = 60 cm, at what rate is thermal energy
being generated in the resistor at the instant the speed of
the bar is equal to 4.2 m/s?
[7.1 W]
4. An AC generator consists of 6 turns of wire. Each turn has an
area of 0.040 m2. The loop rotates in a uniform field (B = 0.20
T) at a constant frequency of 50 Hz. What is the maximum
induced emf?
[15 V]
5. A long solenoid (n = 1 500 turns/m) has a cross-sectional
area of 0.40 m2 and a current given by I = (4.0 + 3.0t2) A, where
t is in seconds. A flat circular coil (N = 300 turns) with a crosssectional area of 0.15 m2 is inside and coaxial with the
solenoid. What is the magnitude of the emf induced in the coil
at t = 2.0 s?
[1.0 V]
2