I am a high school physics teacher and came across some issues today that I am unable to explain.
We made a circuit with an $11$ V power source connected to a $100~k\Omega$ resistor and $100~\mu F$ capacitor. We used a Vernier voltage probe to observe the potential across the capacitor increase. The potential increased to about $6$ V and stayed relatively constant. I'm really unsure of why it would not go up to $11$ V.
We also observed the capacitor discharging by removing the power source from the circuit. It seemed to discharge down to about 0.2V and stay around there. I short circuited the capacitor to completely drain it and the potential went down to zero but then slowly built back up to 0.2V. We discovered that the voltage probe itself seems to be charging the capacitor and that just doesn't make sense to me.
Big thanks in advance to anybody that can help me make sense of either or both of these issues.