Technician A says that pressure below atmospheric pressure is called vacuum and is measured in inches of mercury (Hg). Technician B says that a manifold absolute pressure (MAP) sensor uses a low vacuum in the sensor to determine the pressure. Who is right?

Technician A is Right and Technician B is wrong

Explanation:

Technician A is right, If we take standard atmospheric pressure as reference then pressure below atmospheric pressure is known as "vacuum" and is usually measured in inches of mercury Hg. On the other hand, the pressure above the atmospheric pressure is simply called "pressure".

Technician B is wrong, The MAP sensor compares manifold vacuum to a perfect vacuum to determine the pressure.The manifold absolute pressure (MAP) sensor is used in the electronic control system of an internal combustion engine.

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).