PHY2049 - GENERAL PHYSICS II
PRACTICE QUIZ 24

Below you will find a set of 5 conceptual and numerical revision questions selected randomly from lots of questions I have put together covering the material in Chapter 24, "Electrostatic Energy and Capacitance". This includes questions on the electrostatic potential energy, capacitance, combinations of capacitors, storage of electrical energy and dielectrics. When you have finished the quiz, click on the "Submit Quiz" button at the bottom and within seconds it will be automatically graded and the results returned to you!

To select a new set of questions click on the "Reload" or "Refresh" button on your browser. You may find some of the questions duplicated but that's the nature of a random selection. Try it a few times ... it's not fattening and you may learn something!

Many thanks to Mark Wood for producing the quiz-maker code.


Q1: If the area of the plates of a parallel-plate capacitor is doubled, the capacitance is

not changed
doubled
halved
increased by a fgactor of 4
decreased by a factor of 1/4

Q2: You connect three capacitors as shown in the diagram below.

If the potential difference between A and B is 12 V, what is the energy stored in C3 if C1 = 5.0 μF, C2 = 4.0 μF and C3 = 3.0 μF?

1.6 × 10-4 J
4.1 × 10-5 J
1.2 × 10-4 J
4.1 × 10-4 J
1.6 × 10-3 J


Q3: A parallel plate air capacitor is connected to a constant-voltage battery. If the separation between the plates is doubled while the capacitor remains connected to the battery, the energy stored in the capacitor

quadruples
doubles
remains unchanged
drops to one half its previous value
drops to one fourth its previous value.

Q4: If a dielectric is inserted between the plates of a parallel-plate capacitor that is connected to a 100 V battery,

the potential difference across the capacitor decreases.
the electric field between the plates decreases.
the electric field between the plates increases.
the charge on the capacitor plates decreases.
the charge on the capacitor plates increases.

Q5: A 10.0 μF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0 μF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate. How much energy is "lost" when the two capacitors are connected together?

33 × 10-6 J
42 × 10-6 J
63 × 10-6 J
130 × 10-6 J
560 × 10-6 J

Click on the Submit Quiz button below to have your quiz automatically graded.

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