Electric Potential, Voltage, and Capacitance (4C) Practice Test

A lab group reports that a capacitor has a measured value of $2.0\ \text{V}$, and they plan to “increase the capacitance to 5.0 V” by changing plate area. Which statement is most consistent with correct interpretation of electric potential and capacitance?

A neuron membrane can be approximated as a capacitor. In a simplified preparation, the membrane capacitance is $C_m=100\ \text{pF}$ and the membrane potential is held at $V_m=-70\ \text{mV}$ relative to the extracellular fluid. If $C_m$ increases to $200\ \text{pF}$ while the membrane potential is actively clamped at the same $V_m$ (ideal voltage clamp), which statement is most consistent with capacitance behavior? (Use $Q=CV$; sign indicates plate polarity.)