Title: Inductor/energy storage elements - final questions

Fill in the missing words

Q: The electrical energy consumed by an inductor is stored in the form of a [...].
A: magnetic field

Q: The inductance of an inductor is
- directly proportional to the number of turns of the wire (correct)
- inversely proportional to the cross-sectional area of the coil
- inversely proportional to the length of the coil (correct)
- directly proporional to the permeability (correct)

In the circuit below, the switch has been closed for a very long time. At t=0, the switch opens. Determine the capacitor voltage and the inductor current immediately after the switch opens (t=0).

[Image: circuit]

Solution

As the switch has been opened for a very long time, the cirucit can be simplied as follows:

- the capacitor acts like an open circuit
- the inductor acts like a short circuit

Hence:

[Image: equations]

[Image: simplified circuit]