Ans. It flows in the direction A B C D (fig. 165), as is easily ascertained by aid of Fleming’s rule.
Ques. What is the path of the current to the external circuit?
Ans. It flows out through brush M (fig. 165) and returns through brush S, thus making M positive and S negative.
Ques. What occurs during the second half of the revolution?
Ans. The wire A B (fig. 166), which before was moving in a downward direction, moves in an upward direction; hence, the current is reversed and flows around the loop in the direction A D C B (fig. 166), going out through brush S and returning through brush M. This makes M negative and S positive.
Ques. What may be said of the electromotive force during the second half of the revolution?
Ans. It varies in a similar manner as in the first half of the revolution; that is, the magnetic lines are cut with increasing rapidity during the third quarter, and with decreasing rapidity during the fourth quarter of the revolution, which causes the electromotive force to increase and decrease during these intervals.
The cycle of events just described may be summed up as follows: During the revolution of the loop: