Assignment 9
Which describes the magnetic field lines near a long straight wire carrying current? - ANS-They
form concentric circles around the wire, in a plane perpendicular to the wire.
What do we calculate if we integrate length element ds around a full circle? - ANS-the
circumference of the circle
Which currents are included in a calculation of Ampere's law? - ANS-only currents that are
inside the loop of integration
Which is true about the magnetic field lines of a solenoid? - ANS-Internally, they are closely
spaced with a uniform spacing. Externally, they are more widely spaced with a nonuniform
spacing.
Which is true about the magnitude of the magnetic field inside a toroid? - ANS-It is inversely
proportional to the radius.
The magnetic field a distance 2 cm from a long straight current-carrying wire is 2 x 10-5 T. The
current in the wire is: - ANS-2.0 A
A constant current is sent through a helical coil made of flexible wire. The coil: - ANS-tends to
get shorter
A long straight cylindrical shell carries current i uniformly distributed over its cross section. The
magnitude of the magnetic field is greatest: - ANS-at the outer surface of the shell
Which describes the magnetic field lines near a long straight wire carrying current? - ANS-They
form concentric circles around the wire, in a plane perpendicular to the wire.
What do we calculate if we integrate length element ds around a full circle? - ANS-the
circumference of the circle
Which currents are included in a calculation of Ampere's law? - ANS-only currents that are
inside the loop of integration
Which is true about the magnetic field lines of a solenoid? - ANS-Internally, they are closely
spaced with a uniform spacing. Externally, they are more widely spaced with a nonuniform
spacing.
Which is true about the magnitude of the magnetic field inside a toroid? - ANS-It is inversely
proportional to the radius.
The magnetic field a distance 2 cm from a long straight current-carrying wire is 2 x 10-5 T. The
current in the wire is: - ANS-2.0 A
A constant current is sent through a helical coil made of flexible wire. The coil: - ANS-tends to
get shorter
A long straight cylindrical shell carries current i uniformly distributed over its cross section. The
magnitude of the magnetic field is greatest: - ANS-at the outer surface of the shell
