JAMB - Physics (1981 - No. 29)
Alternating current can induce voltage because it has a
ripple value
varying magnetic field
weaker magnetic field than direct current
stonger magnetic field than direct current
high peak value
解释
Due to the change in the voltage in an AC, which either increases or decreases, the magnetic field around it is alwats eithercollapsing or expanding (varying magnetic field).