Univ Physics 2 - True/False/Increase/Decrease/Remain the same/Conceptual questions
These questions will be discussed on Friday – no solutions will be posted.
1. You have a pair of resistors – increasing the resistance of one of them will always increase the
resistance of the combination (the effective resistance) – true/false - explain?
2. Why does a “regular” battery “die?”
3. What is the conceptual explanation for why resistance might increase with temperature? Decrease?
4. Current splits as it comes to a set of parallel known resistors .. how can we tell the magnitude of each
side current is correct?
5. To make an ammeter from a galvanometer and a resistor – should it be large or small – in series or
parallel … why?
6. To make a voltmeter from a galvanometer and a resistor – should it be large or small – in series or
parallel … why?
7. In a DC RC circuit, as the capacitor is charging, what variables exponentially rise, and which fall?
8. In a DC RC circuit, as the capacitor is discharging, what variables exponentially rise, and which fall?
9. You have a DC RC discharging circuit – if we add another resistor in parallel, will the rate of
discharge increase/decrease/remain the same – explain.
10. You have a DC RC discharging circuit – if we add another capacitor in parallel, will the rate of
discharge increase/decrease/remain the same – explain.
11. As a capacitor is charging in a circuit – if we look immediately after we throw the switch, what does
the capacitor “look like” – if we look at it a long time after we throw the switch, what does it “look
like”?
12. A disconnected capacitor has a charge on it – the plate separation increases .. what happens to the
voltage and the charge (increase/decrease/remain the same)?
13. A capacitor is connected to a battery – the area of the plates increase … what happens to the voltage
and the charge (increase/decrease/remain the same)?
14. What is one conceptual way to remember that two capacitors in parallel have more capacitance than
one?
15. In what three ways does a dielectric “help” a parallel plate capacitor?
16. If you remove a dielectric from between the plates of a capacitor, the charge on the plates will
always decrease (true/false)?
17. What are the “order” of the voltages in an RLC AC circuit (which peaks first, second, etc.) – also
explain how you can tell where Etotal fits into the picture.
18. Leaving the resistance and the Etotal alone, how can you get more current out of an AC RLC
circuit?
19. Which circuit element did we use to make a high pass filter (with AC and R and L or C) – and why?
20. Which circuit element did we use to make a low pass filter (with AC and R and L or C) – and why?
21. The velocity of a moving charge will always be perpendicular to the magnetic field, true/false –
explain?
22. The force on a moving charge will always be perpendicular to the magnetic field, true/false –
explain?
23. Under the right circumstances, a magnetic field can increase the speed of a moving charge –
true/false - explain?
24. With an electric field pointing north, and a magnetic field pointing into the paper – a plus charge
moving toward the East (from the West) could pass through the crossed fields without deflection
(given the right values of the field magnitudes) – true/false - explain?
25. How does the Hall effect explain that negative charges actually move?