Hawkins Electrical Guide v. 01 (of 10) / Questions, Answers, & Illustrations, A progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications

by N. Hawkins

current = ((n - n′)/t)/R or, (n - n′)/(Rt) (3)

Now in equation (3) if there be a decrease in the number of lines cut n′ will be less than n hence the current will be positive (+); again, if the lines increase n′ will be greater than n, which will give a minus value, that is, the current will be negative or in a reverse direction.

6. The approach and recession of a conductor from a magnet pole will yield currents alternating in direction.

Since the strength of the field depends on the proximity to the pole, the approach and recession of a conductor involve an increase and decrease in the rate of cutting of magnetic lines, hence a reversal of current.

7. The more rapid the motion, the higher will be the induced electromotive force.

In other words, the greater the number of lines cut per unit of time, the higher will be the voltage.

8. Lenz’s law. The direction of the induced current is always such that its magnetic field opposes the motion which produces it.

This is illustrated in figs. 130 and 131.