Final answer:
In the context of physics, 'Q' often stands for Quality factor or relates to Quantum mechanics, and 'V' stands for Voltage. 'SC' in 'QSC' does not correspond to a standard term in physics.
Step-by-step explanation:
The letters 'QSC' and 'V' represent different concepts depending on the context. In most scientific contexts, 'Q' typically stands for Quality factor, which is a dimensionless parameter that describes how underdamped an oscillator or resonator is, or it could stand for Quantum mechanics, a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. The 'SC' in 'QSC' does not have a standard definition in physics, but it often implies system control in a more general context. Therefore, options 1, and 3 provided in the question do not correspond with the standard terminology used in physics. On the other hand, 'V' commonly stands for Voltage, a measurement of the electric potential difference between two points.