Answer:
He is testing for voltage drop (voltage drop test)
Explanation:
Connecting the red lead of a voltmeter to the B+ output to an ac generator and black lead to a battery +ve terminal measures the voltage drop in the circuit when the engine is turned ON and all electrical accessories too.
with this he knows if the alternator is charging the battery.
Mass is the actual amount of material contained in a body and is measured by kg, gm, etc. Whereas weight is the force extorted by the gravity on that object mg. Note that mass is independent of everything but weight is different on earth, moon, etc.
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction