Final answer:
The student's question is regarding resistance, voltage, and current measurements in a series circuit, explaining power supply and dissipation, as well as effects of adding resistors in parallel and reasons for battery depletion. It considers total resistance calculation, use of Ohm's law, and strategies for finding unknown values in electrical circuits.
Step-by-step explanation:
In addressing the student's question related to a circuit containing three resistors in series with values of 5 Ω, 7.5 Ω, and 11 Ω, the total resistance can be found by simply adding these values together, since resistors in series add directly. Concerning the measurement of voltages and currents, they can be captured across and before or after each resistor, respectively, also considering the effects before and after parallel branches if any are present. To understand the power supplied by the voltage sources (V) and dissipated by the resistors (R), we refer to the formula P = IV, where I refers to the current in amperes and V is the potential difference in volts. In the case of power dissipated by resistors, P can also be found using P = I²R where R is the resistance value.
When resistors are added in parallel, the total resistance of the circuit decreases, which is counterintuitive when compared to series circuits. This is because the total available path for current flow increases with each resistor added in parallel. However, why batteries go flat is related to the chemical processes inside them being exhausted, preventing them from maintaining the voltage necessary to produce the current.
The strategy for finding unknown resistances in a series-connected circuit involves summing them up with known resistances to find the total or equivalent resistance, and using that information along with the total voltage to solve for unknowns, keeping in mind that the current remains the same through all components in series.