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1. ### Residential PF Caps -- are they for real?

The typical residential home in the US has a peak load power factor in the range of 0.90 to 0.95 lagging. The only way adding capacitors is going to save you on your electric bill is if your electric utility bills you in...

5 Answers · Science & Mathematics · 06/04/2008

2. ### (Electrical Circuits) What is the pf?

Cos of the phase angle in the impedance coil circuit = .74 Phase angle of impedance coil circuit = arc cos .74 = 42.27 degrees Inductive vars = (sin 42.27 degrees) x 269 VA = 180.93 var Watts of impedance coil = p.f. x VA = .74 x 269 = 199 Watts...

2 Answers · Science & Mathematics · 01/02/2010

3. ### a varactor diode has C0 equal to 320 pF?

Varactor characteristics aren't linear http://spraguegoodman.com/pdfs/950.pdf The only way to plot a curve would be to either do an actual Vr versus capacitance or simulate it on one of the many electronic simulation programs. Assuming you meant 200μ...

2 Answers · Science & Mathematics · 23/02/2012

4. ### A 2400 pF air-gap capacitor is connected to a 8.0 V battery. ?

Initial charge is Q = CV = 19.2 nC Mica has a dielectric constant of about 7 (varies a lot, depending on type and source) so the capacitance changes to 2.4 nF x 7 = 16.8 nF new charge is 16.8 nF x 8 = 134...

2 Answers · Science & Mathematics · 05/12/2008

5. ### A 80-pF capacitor is immersed in silicone oil...?

assuming it was an air dielectric and its capacitance went up by 2.6 times Q=CV = 80e-12*2.6*24 = 5e--9 coulombs energy storage = 1/2 C*V^2 = 1/2*5e-9*24 = 60e-9 Joules

3 Answers · Science & Mathematics · 15/09/2013

6. ### A 6.0-pF capacitor is needed to construct a circuit.?

The first answer is correct. If you really need other answers, you can combine 9 caps in parallel and then put 6 sets of them in series. Or 18 caps and 12 sets. There are an infinite number of...

2 Answers · Science & Mathematics · 20/11/2013

7. ### How do the mechanics pf a blender work?

Blender is a simple series universal motor that can be run on either AC or DC power source. It has a pair of carbon made brushes. It also has different turns of field windings connect to the selector where select the different...

2 Answers · Science & Mathematics · 12/03/2011

8. ### The square plates of a 2000-pF capacitor measure 20 mm by 20 mm and are separated by a dielectric that is 0.27?

Given parameters of capacitor are: Capacitance C = 2000pF = 2000 x 10-12pF (1pF = 10-12F) Separation of plates = thickness of dielectric = 0.27mm = 27 x 10-5m Plates are square with dimension 20mm...

2 Answers · Science & Mathematics · 03/01/2013

9. ### How many 0.25-pF capacitors must be connected in parallel in order to store 1.2µC of charge when connected to?

Q = C*V C = Q/V = (1.2*10^-6/10) = 1.2*10^-7 Capacitors in parallel add, so if we need n capacitors C = 1.2*10^-7 = n*0.25*10^-12 n = 1.2*10^-7/(0.25*10^-12) = 4.8*10^5 = 480,000 <<<

1 Answers · Science & Mathematics · 11/02/2014

10. ### How is CFL bulbs so effecient if the have a power factor of 0.5-0.6?

pf has little to do with efficiency, which is ratio of output power to input power. If pf is 0.5, and VA is 200, then power is 100watts. If...

3 Answers · Science & Mathematics · 20/11/2012