Magnetic Fields

What is the formula for calculating the magnetic force on a charge moving in a magnetic field?

• F = qvBcosine(theta)

• F = qvBtan(theta)

• F = qvBcos(theta)

• F = qvBsin(theta)

How is the magnetic field due to a current in a straight wire related to the distance from the wire?

• Inverse square law

• Exponential relationship

• Directly proportional to the distance

• Constant with distance

Describe the magnetic field pattern around a bar magnet.

• The magnetic field pattern is linear and extends infinitely in all directions.

• The magnetic field pattern is only visible under a microscope.

• The magnetic field pattern is triangular around the magnet.

• Closed loops that emerge from the north pole, curve around the magnet, and re-enter at the south pole.

Explain how the magnetic field varies inside and outside a current loop.

• The magnetic field outside a current loop is concentrated and stronger.

• The magnetic field inside and outside a current loop is the same.

• The magnetic field inside a current loop is weaker than outside the loop.

• The magnetic field inside a current loop is concentrated and stronger, while outside the loop it is more spread out and weaker.

What is the direction of the magnetic field around a straight current-carrying wire?

• Straight lines perpendicular to the wire

• Concentric circles with the wire at the center

• Random chaotic pattern

• Spiral pattern around the wire

What is the Biot-Savart law and how is it used to calculate magnetic fields?

• The Biot-Savart law is used to calculate magnetic fields by considering only the total current in a wire.

• The Biot-Savart law is used to calculate electric fields by integrating the contributions of infinitesimal charge elements along the path of interest.

• The Biot-Savart law is used to calculate gravitational fields by integrating the contributions of infinitesimal mass elements along the path of interest.

• The Biot-Savart law is used to calculate magnetic fields by integrating the contributions of infinitesimal current elements along the path of interest. This allows for the determination of the magnetic field strength and direction at any point in space surrounding the current-carrying wire.

Define magnetic dipole moment and explain its significance in magnetic fields.

• The magnetic dipole moment is significant in magnetic fields as it helps describe the behavior of magnetic materials in external fields, such as how they align with or against the field. It is crucial in understanding phenomena like magnetism, magnetic materials, and applications like magnetic resonance imaging (MRI).

• The magnetic dipole moment is only relevant in electrical fields.

• Magnetic dipole moment has no significance in magnetic fields.

• The magnetic dipole moment is a measure of the strength of a magnetic field.

How is the torque experienced by a magnetic dipole in an external magnetic field related to its potential energy?

• Torque is related to potential energy through the equation: Torque = -∇(magnetic dipole moment dot product with external magnetic field)

• Torque is directly proportional to the square of the potential energy

• Torque is inversely related to the potential energy

• Potential energy has no effect on the torque experienced by a magnetic dipole

What role does the right-hand rule play in determining the direction of the magnetic field around a current-carrying conductor?

• It is used to predict the direction of the induced magnetic field relative to the direction of the current flow.

• It determines the magnitude of the magnetic field only.

• It is irrelevant to the direction of the magnetic field.

• It predicts the temperature of the conductor.

What is the significance of the magnetic flux density in understanding magnetic fields?

• It indicates the resistance a material poses to the formation of a magnetic field.

• It measures the concentration of magnetic field lines per unit area, providing insight into the field's strength and direction.

• It is only relevant in the context of gravitational fields.

• It describes the thermal energy produced by a magnetic field.