01. One of the following is not a source of magnetostatic fields:
a. A dc current in a wire.
b. A permanent magnet.
c. An accelerated charge.
d. An electric field Linearly changing with time.
e. A charged disk rotating at uniform speed.
2. Which of these statements is not characteristic of a static magnetic field?
a. It is solenoidal.
b. It is conservative.
c. It has no sinks or sources.
d. Magnetic flux lines are always closed.
e. The total number of flux lines entering a given region is equal to the total number of flux lines leaving the region.
3. Two identical circular coaxial coils carry current I in opposite directions. The magnetic field H at a point on the axis, midway between the coils is:
a. Zero.
b. The same as that produced by one coil.
c. Twice that produced by one coil.
d. Half that produced by one coil.
