What are capacitors used for and how are they constructed?
Used for storing electric charge
2 parallel plates separated by an insulator (dielectric)
What are the 3 factors that affect capacitors and give a lil detail
Plate area - proportional
Distance between plates - inversely proportional
Dielectric constant - proportional - material permittivity
What is leakage resistance?
Measure of capacity quality - determines how long it will store a charge before it ‘leaks away’
What is working voltage?
Max direct current voltage that can be applied - printed on capacitor
What is dialectric strength?
Measure of ability of dielectric to withstand a specified potential across a given thickness of the material (V/mm)
What is a resistor box for and what are its main components?
Substitution box in place of a standard resistor
6 rotary switches each with 10 resistors
Describe the procedure for determining the calibration status of a resistor decade box
Check label make sure it is present and unbroken
Describe the serviceability test for a resistor decade box
- Multimeter continuity test - baseline ohms may be subtracted from future tests
- Set box to resistance required
- Connect multimeter - should be under tolerance of 1% - continue to check for every new resistance selection
Which capacitor has the symbol with an arrow through it?
Variable capacitor
Describe the capacitor symbols for a polarised capacitor
one line is a curve | one has a lil plus sign next to it
