Electrical Circuits: Capacitors Flashcards
Capacitance acts to store electrical energy as
electric field
As capacitor plate area increases, all other things being equal
The capacitance increases
As the spacing between plates in a capacitor is made smaller, all other things being equal
The capacitance increases
A material with a high dielectric constant
Acts to increase capacitance per unit volume
A capacitance of 100 pF is the same as ______ μF
0.0001 μF
Five 0.050-μF capacitors are connected in parallel. The total capacitance is
0.25 μF
Five 0.050-μF are connected in series, the total capacitance will be
0.010 μF
Two capacitors are in series. Their values are 47 pF and 33 pF. The composite value is
19 pF
Three capacitors are in parallel. Their values are 0.0200 μF, 0.0500 μF and 0.10000 μF. The total capacitance is
0.170 μF
Air works well as a dielectric mainly because it
Has low loss
Which of the following is not a characteristic of mica capacitors?
A. High efficiency.
B. Small size.
C. Capability to handle high voltages.
D. Low loss.
Small size
A disk ceramic capacitor might have a value of A. 100 pF. B. 33 μF. C. 470 μF. D. 10,000 μF
100 pF
A paper capacitor might have a range of:
1nF to 1μF.
An air-variable capacitor might have a range of
1 pF to 100 pF.
Which of the following types of capacitors is polarized? A. Paper B. Mica. C. Interelectrode. D. Electrolytic.
Electrolytic
If a capacitor has a negative temperature coefficient
Its value decreases as the temperature rises.
A capacitor is rated at 33 pF, plus or minus 10 percent. Which of the following capacitances is outside the acceptable range?
37 pF
A capacitor, rated at 330 pF, shows an actual value of 317 pF. How many percent off is its value?
3.9
a two terminal passive device that stores energy as electric field
capacitance
it is how much charge you can hold per voltage
capacitance
a 330pF capacitor and a 220pF capacitor are each connected across a 6Vdc source . The voltage across the 330pF capacitor is?
6V
unit for capacitance
Farads (F)
Unit for charge
Coloumb (C)
How to find constant value of electron charge in the calculator
shift+const+47
What is the constant value of an electron charge
1.602x10^-19
Is voltage(V) and electric potential energy(V) similar?
Voltage is the difference in electric potential energy. or the change in electric potential energy
dielectric constant (k) of the insulator air
1.006
what is ghrdielectric constant (k) of a vacuum
1
what is the dielectric constant of the insulator quartz?
4.3
what is the dielectric constant (k) of water
80
How to input the value of absolute permitivity (Eo) on your calculator
shift+const+32
What is the value of absolute permitivity?
8.85x10^-12
to get the the permitivity (E):
dielectric k (aka relative permitivity) multiplied by the absolute permitivity
the formula to get the electric field of the capacitor is
E= Voltage/distance between plates
current flow from _____ electric potential to _____ electric potential
high, low
In metals, ______ move and ______ does not.
electrons, protons
