Chapter 20 Physics II

A solenoid 20 cm long is wound with 5000 turns of wire. What magnetic field is produced at the center of the solenoid when a current of 10 A flows?

0.0063 T

What is the force per meter on a straight wire carrying 5.0 A when it is placed in a magnetic field of 0.020 T? The wire makes an angle of 27 degrees with respect to the magnetic field lines.

0.045 N/m

A proton travels through a potential of 1.0 k and then moves into a magnetic field of 0.040 T. What is the radius of the proton's resulting orbit?

0.11 m

A proton has a speed of 3.0 ̨ 106 m/s in a direction perpendicular to a uniform magnetic field, and the proton moves in a circle of radius 0.20 m. What is the magnitude of the magnetic field?

0.16 T

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. At what point between the two wires are the contributions from the two wires the same?

0.16 m from the 20 A wire

A circular loop of wire of radius 0.50 m is in a uniform magnetic field of 0.30 T. The current in the loop is 2.0 A. What is the magnetic torque when the plane of the loop is parallel to the magnetic field?

0.47 m*N

A circular loop of wire of cross-sectional area 0.12 m2 consists of 200 turns, each carrying 0.50 A. It is placed in a magnetic field of 0.050 T oriented at 30e to the plane of the loop. What torque acts on the loop?

0.52 m*N

A circular loop carrying a current of 2.0 A is in a magnetic field of 3.5 T. The loop has an area of 0.12 m2 and its plane is oriented at a 37e angle to the field. What is the magnitude of the magnetic torque on the loop?

0.67 m*N

A wire carries a current of 10 A in a direction of 30 degrees with respect to the direction of a 0.30-T magnetic field. Find the magnitude of the magnetic force on a 0.50-m length of the wire.

0.75 N

A proton is accelerated from rest through 500 . It enters a magnetic field of 0.30 T oriented perpendicular to its direction of motion. Determine the radius of the path it follows.

1.1 cm

An electron moves with a speed of 5.0 X10^4 m/s perpendicular to a uniform magnetic field of 0.20 T. What is the magnitude of the magnetic force on the electron?

1.6 X 10^-15

What is the strength of a magnetic field 5.0 cm from a long straight wire carrying 4.0 A of current?

1.6 X 10^-5

A doubly charged ion with velocity 6.9 ̨ 106 m/s moves in a path of radius 30 cm in a magnetic field of 0.80 T in a mass spectrometer. What is the mass of this ion?

11 X 10^-27 kg

How many turns should a 10-cm long solenoid have if it is to generate a 1.5 ̨ 10-3 T magnetic field on 1.0 A of current?

119

A high power line carrying 1000 A generates what magnetic field at the ground, 10 m away?

2.0 X 10^-5

At what distance from a long straight wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth's magnetic field of about 5.0 X 10-5 T?

2.0 cm

Four long parallel wires each carry 2.0 A in the same direction. They are parallel to the z-axis, and they pass through the corners of a square of side 4.0 cm positioned in the x-y plane. What magnetic field does one of the wires experience due to the other wires?

2.1 X 10^-5 T

What is the magnetic moment of a rectangular loop of 120 turns that carries 6.0 A if its dimensions are 4.0 cm ̨ 8.0 cm?

2.3 A*m^2

An electron traveling due north with speed 4.0 X10^5 m/s enters a region where the Earth's magnetic field has the magnitude 5.0 X 10-5 T and is directed downward at 45 degrees below horizontal. What force acts on the electron?

2.3 X 10^-18

Two long parallel wires carry currents of 5.0 A and 8.0 A in the opposite direction. The wires are separated by 0.30 m. Find the magnetic force per unit length between the two wires.

2.7 X 10^-5 repulsive

An electron moves with a speed of 8.0 ̨ 106 m/s along the +x axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60e to the +x axis and lying in the xy plane. Calculate the magnetic force of the electron.

2.8 X 10^-12

A solenoid with 500 turns is 0.10 m long and carries a current of 4.0 A. What strength of magnetic field will it have at its center?

25 mT

What is the magnetic field at the center of a circular loop of wire of radius 4.0 cm when a current of 2.0 A flows in the wire?

3.1 X 10^-5 T

An electron moves with a speed of 8.0 ̨ 106 m/s along the +x axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60e to the +x axis and lying in the xy plane. Calculate the acceleration of the electron.

3.1 X 10^18

A very long straight wire carries a current of 25 A. What is the magnitude of the magnetic field at a distance of 0.15 m from the wire?

3.3 X 10-5 T

A proton travels at a speed of 5.0 ̨ 10^7 m/s through a 1.0-T magnetic field. What is the magnitude of the magnetic force which acts on the proton if the angle between the proton's velocity and the magnetic field vector is 30 degrees?

4.0 X 10^-12

A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to cancel the weight of

4.9 A

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnetic field midway between the two wires?

5.0 X 10^-5

A beam of electrons is accelerated through a potential difference of 10 k before entering a velocity selector. If the B-field of the velocity selector has a value of 0.010 T, what value of the E-field is required if the particles are to be undeflected?

5.9 X 10^5 V/m

How much current must flow for 1.0 ̨ 10-3 T of magnetic field to be present 1.0 cm from a wire?

50 A

In a mass spectrometer, a single-charged particle (charge e) has a speed of 1.0 ̨ 106 m/s and enters a uniform magnetic field of 0.20 T. The radius of the circular orbit is 0.020 m. What is the mass of the particle?

6.4 X 10^-28 kg

Two long parallel wires carry currents of 10 A in opposite directions. They are separated by 40 cm. What is the magnetic field in the plane of the wires at a point that is 20 cm from one wire and 60 cm from the other?

6.7 X 10^-6 T

A circular wire loop of area 0.25 m2 carries a current of 5.0 A. The coil lies in a horizontal plane with the current flowing in the counterclockwise direction when viewed from above. At this point, the Earth's magnetic field is 1.2 ̨ 10-4 T directed 60e below the horizontal. What is the magnitude of the torque which acts on the loop?

7.5 X 10^-5 m*N

A proton moving at 4.0 X 10^4 m/s horizontally enters a region where a magnetic field of 0.13 T is present, directed vertically downward. What force acts on the proton?

8.3 X 10^-16

How much current must pass through a 400 turn coil 4.0 cm long to generate a 1.0-T magnetic field at the center?

80 A

A 2.0-m wire carrying a current of 0.60 A is oriented parallel to a uniform magnetic field of 0.50 T. What is the magnitude of the force it experiences?

Zero

A circular loop of wire of radius 0.50 m is in a uniform magnetic field of 0.30 T. The current in the loop is 2.0 A. What is the magnetic torque when the plane of the loop is perpendicular to the magnetic field?

Zero

A stationary proton is in a uniform magnetic field of 0.20 T. What is the magnitude of the magnetic force on the proton?

Zero