A student removes the split-ring commutator from a working model of a d.c. motor and connects the coil ends directly to two fixed wires. After giving the coil a small push, which observation is most likely?
a) The coil continues to rotate smoothly in the same direction
b) The coil reverses its direction of rotation after every half-turn and speeds up
c) The coil turns about half a revolution and then comes to rest
d) The coil keeps oscillating back and forth about its starting position without completing a full revolution