Atechnician connects one lead of a digital voltmeter to the positive (+) terminal of the battery and the other meter lead to the battery terminal (b) of the starter solenoid and then cranks the engine. during cranking, the voltmeter displays a reading of 878 mv. technician a says that this reading indicates that the positive battery cable has too high resistance. technician b says that this reading indicates that the starter is defective. which technician is correct?

most voltage drop calculators want the distance between the source and destination. then internally, they double it so both the source and return wires are calculated. but you need to know which distance the calculator uses so you're not half of what you should be or double what you should be.

most circuit breakers will not take a #6 directly, so the electrician will have to splice on a smaller pigtail. you also have to upsize the grounding wire when you upsized the ungrounded (hot) wire (see note in 250.122). this will preclude using most cable assemblies, as a cable with #6 copper will most likely only have a #10 grounding conductor. you need a #6 grounding conductor if the circuit is 20a. a #8 cable is no better, as it will have a #10 grounding conductor too. but most 20a breakers will take a #8 directly.

in your related post, you didn't say what type of load this is. if it is a light or heater, voltage drop won't be a big issue. if this is a motor, the current needs are huge at startup and the voltage drop can pose a problem. if this is a motor, knowing if the motor is under much load during startup will answer the voltage drop effect (a saw is easier to start than a compressor).

the bal will not change its velocity.

increase masses, decrease separation

b. a lightning bug, plug of grass, and a worm