Quiz on Magnetic Fields

Which statement is incorrect regarding the magnetic field?

• The magnetic field is a force field caused by electric current or magnets.

• The magnetic field is a form of matter existing around electric current or magnets.

• The magnetic field is a form of matter existing around a stationary electric charge.

• The manifestation of the magnetic field is the appearance of magnetic force acting on electric current or magnets placed within it.

The magnetic field lines are curves drawn in space with a magnetic field such that

• the normal at every point coincides with the direction of the magnetic field at that point.

• the tangent at every point coincides with the direction of the magnetic field at that point.

• the normal at each point forms a constant angle with the direction of the magnetic field.

• the tangent at every point forms a constant angle with the direction of the magnetic field.

The magnetic field lines are drawn in space with a magnetic field such that the tangent to it at each point

• coincides with the direction of the magnetic force acting on the current at that point.

• coincides with the direction of the magnetic field at that point.

• is perpendicular to the magnetic field at that point.

• is perpendicular to the direction of the magnetic force acting on the current at that point.

Which statement is incorrect? The basic property of the magnetic field is to exert magnetic force on

• a stationary electric charge placed within it.

• a magnet placed within it.

• a moving electric charge within it.

• an electric current placed within it.

A uniform magnetic field is a magnetic field that has

• curved magnetic field lines.

• the same magnetic flux density vector at all points.

• circular magnetic field lines.

• the same magnitude of magnetic flux density at all points.

A uniform magnetic field is a magnetic field where the magnetic field lines are

• curved, non-intersecting, and equidistant.

• curved and non-intersecting.

• straight and parallel.

• straight, parallel, and equidistant.

The direction of the magnetic force acting on a current follows the rule of

• the left hand.

• the right hand.

• the right fist.

• the left fist.

A wire frame carrying current I placed in a uniform magnetic field, with the plane of the frame perpendicular to the magnetic field lines (as shown in the figure). Which conclusion is correct about the magnetic force acting on the sides of the frame?

• The resultant of the magnetic forces acting on the sides has a non-zero magnitude.

• It is perpendicular to the plane of the frame.

• It lies in the plane of the frame, perpendicular to the sides and tends to stretch the frame.

• It lies in the plane of the frame, perpendicular to the sides and tends to compress the frame.

The concept of magnetic flux is used to describe

• the number of magnetic field lines passing through a certain area.

• the strength of the magnetic field.

• the direction of the magnetic flux density vector.

• the distribution of magnetic field lines.

Which of the following statements is incorrect regarding electromagnetic induction?

• In electromagnetic induction, a changing magnetic field can generate an electric current.

• The induced current can arise from the changing magnetic field of an electric current or the magnetic field of a permanent magnet.

• The induced current in a circuit only exists when there is a changing magnetic flux through the circuit.

• The induced current appears in a closed circuit that is stationary in a constant magnetic field.