A rectangular coil of wire can rotate in a magnetic field. The ends of the coil are soldered to the two halves of a split ring. Two carbon brushes are made to press lightly against the split ring and when these are connected in circuit with a battery and rheostat, the coil rotates. This is a description of
-
A.
a suspended- coil vanometer -
B.
a moving-cell ammeter -
C.
a d.c generator -
D.
an electric motor -
E.
an induction coil,