Final Exam Part 2 (Ch 22-25) ACTUAL UPDATED QUESTIONS AND CORRECT
ANSWERS
A conducting loop has an area of 0.065 m2 and is
positioned such that a uniform magnetic field is
perpendicular to the plane of the loop. When the
magnitude of the magnetic field decreases to 0.30 T in
0.087 s, the average induced emf in the loop is 1.2 V. What
is the
initial value of the magnetic field?
A 250-turn solenoid carries a current of 9.0 A. The radius
of the solenoid is 0.075 m; and its length is 0.14 m.
Determine the magnetic flux through the circular cross-
sectional
area at the center of the solenoid.
The figure shows a uniform, 3.0-T magnetic field that is
normal to the plane of a conducting, circular loop with a
resistance of 1.5 Ω and a radius of 0.024 m. The magnetic
field is directed out of the paper as shown. What is the
average current around the loop if the magnitude of the
magnetic field is doubled in 0.4 s? Note: The area of the
non-circular portion of the wire is considered negligible
compared to that of the circular loop.
A single conducting loop with an area of 2.0 m2 rotates in
a uniform magnetic field so that the induced emf has a
sinusoidal time dependence as shown. Determine the
strength of the magnetic field in which the loop rotates
A solenoid with 1000 turns has a cross-sectional area of
7.0 cm2 and length of 25 cm. How much energy is stored
in the magnetic field of the solenoid when it carries a
current
of 10.0 A?
A 0.100-m long solenoid has a radius of 0.050 m and 1.50
× 104 turns. The current in the solenoid changes at a rate
of 6.0 A/s. A conducting loop of radius 0.0200 m is placed
at the center of the solenoid with its axis the same as that
of the solenoid as shown. a)Determine the mutual
inductance of this combination. b) Determine the induced
emf in the loop.
A transformer changes 120 V across the primary to 1200 V
across the secondary. If the secondary coil has 800 turns,
how many turns does the primary coil have?
, A loop is pulled with a force F to the right to maintain a
constant speed of 8.0 m/s. The loop has a length of 0.15
m, a width of 0.080 m, and a resistance of 200.0 Ω. At the
instant shown, the loop is partially in and partially out of a
uniform magnetic field that is directed into the paper. The
magnitude of the field is 1.2 T. What is the induced current
in
the loop?
A circular copper loop is placed perpendicular to a
uniform magnetic field of 0.75 T. Due to external forces,
the area of the loop decreases at a rate of 7.26 × 10-3
m2/s. Determine the induced emf in the loop
A magnetic field is directed perpendicular to the plane of
a 0.15-m × 0.30-m rectangular coil consisting of 240 loops
of wire. To induce an average emf of -2.5 V in the coil, the
magnetic field is increased from 0.1 T to 1.8 T during a time
interval ∆t. Determine ∆t.
The figure shows a uniform, 3.0-T magnetic field that is
normal to the plane of a conducting, circular loop with a
resistance of 1.5 Ω and a radius of 0.024 m. The magnetic
field is directed out of the paper as shown. If the
magnetic field is held constant at 3.0 T and the loop is
pulled out of the region that contains the field in 0.2 s, at
what rate is energy dissipated in R? Note: The area of the
non-circular portion of the wire is considered negligible
compared to that of the circular loop.
A circular coil has 275 turns and a radius of 0.045 m. The
coil is used as an ac generator by rotating it in a 0.500 T
magnetic field, as shown in the figure. At what angular
speed should the coil be rotated so that the maximum
emf is 175 V?
The figure shows a circular, conducting loop that is
connected to a 5.0-V battery and a switch S. Immediately
after the switch S is closed, the current through the loop
changes at a rate of 15 A/s and the emf induced in the
loop has a magnitude of 5.0 V. Determine the self-
inductance of the coil.
A coil of wire with a resistance of 0.45 Ω has a self-
inductance of 0.083 H. If a 6.0-V battery is connected
across the ends of the coil and the current in the circuit
reaches an equilibrium value, what is the stored energy in
the inductor?
ANSWERS
A conducting loop has an area of 0.065 m2 and is
positioned such that a uniform magnetic field is
perpendicular to the plane of the loop. When the
magnitude of the magnetic field decreases to 0.30 T in
0.087 s, the average induced emf in the loop is 1.2 V. What
is the
initial value of the magnetic field?
A 250-turn solenoid carries a current of 9.0 A. The radius
of the solenoid is 0.075 m; and its length is 0.14 m.
Determine the magnetic flux through the circular cross-
sectional
area at the center of the solenoid.
The figure shows a uniform, 3.0-T magnetic field that is
normal to the plane of a conducting, circular loop with a
resistance of 1.5 Ω and a radius of 0.024 m. The magnetic
field is directed out of the paper as shown. What is the
average current around the loop if the magnitude of the
magnetic field is doubled in 0.4 s? Note: The area of the
non-circular portion of the wire is considered negligible
compared to that of the circular loop.
A single conducting loop with an area of 2.0 m2 rotates in
a uniform magnetic field so that the induced emf has a
sinusoidal time dependence as shown. Determine the
strength of the magnetic field in which the loop rotates
A solenoid with 1000 turns has a cross-sectional area of
7.0 cm2 and length of 25 cm. How much energy is stored
in the magnetic field of the solenoid when it carries a
current
of 10.0 A?
A 0.100-m long solenoid has a radius of 0.050 m and 1.50
× 104 turns. The current in the solenoid changes at a rate
of 6.0 A/s. A conducting loop of radius 0.0200 m is placed
at the center of the solenoid with its axis the same as that
of the solenoid as shown. a)Determine the mutual
inductance of this combination. b) Determine the induced
emf in the loop.
A transformer changes 120 V across the primary to 1200 V
across the secondary. If the secondary coil has 800 turns,
how many turns does the primary coil have?
, A loop is pulled with a force F to the right to maintain a
constant speed of 8.0 m/s. The loop has a length of 0.15
m, a width of 0.080 m, and a resistance of 200.0 Ω. At the
instant shown, the loop is partially in and partially out of a
uniform magnetic field that is directed into the paper. The
magnitude of the field is 1.2 T. What is the induced current
in
the loop?
A circular copper loop is placed perpendicular to a
uniform magnetic field of 0.75 T. Due to external forces,
the area of the loop decreases at a rate of 7.26 × 10-3
m2/s. Determine the induced emf in the loop
A magnetic field is directed perpendicular to the plane of
a 0.15-m × 0.30-m rectangular coil consisting of 240 loops
of wire. To induce an average emf of -2.5 V in the coil, the
magnetic field is increased from 0.1 T to 1.8 T during a time
interval ∆t. Determine ∆t.
The figure shows a uniform, 3.0-T magnetic field that is
normal to the plane of a conducting, circular loop with a
resistance of 1.5 Ω and a radius of 0.024 m. The magnetic
field is directed out of the paper as shown. If the
magnetic field is held constant at 3.0 T and the loop is
pulled out of the region that contains the field in 0.2 s, at
what rate is energy dissipated in R? Note: The area of the
non-circular portion of the wire is considered negligible
compared to that of the circular loop.
A circular coil has 275 turns and a radius of 0.045 m. The
coil is used as an ac generator by rotating it in a 0.500 T
magnetic field, as shown in the figure. At what angular
speed should the coil be rotated so that the maximum
emf is 175 V?
The figure shows a circular, conducting loop that is
connected to a 5.0-V battery and a switch S. Immediately
after the switch S is closed, the current through the loop
changes at a rate of 15 A/s and the emf induced in the
loop has a magnitude of 5.0 V. Determine the self-
inductance of the coil.
A coil of wire with a resistance of 0.45 Ω has a self-
inductance of 0.083 H. If a 6.0-V battery is connected
across the ends of the coil and the current in the circuit
reaches an equilibrium value, what is the stored energy in
the inductor?
