I am requesting support from someone who knows electronic power circuits. I have an AC adapter, input 120VAC, two outputs: 32VDC & 16VDC. I connect a voltmeter to either output and when I plug it in, output is instantly correct but then slowly reduces to zero asymptotically. It will not deliver any output again until is it unplugged and plugged it again. It then jumps to the correct output, then repeats the slow reduction to zero. I know enough to suspect that the slow fade-out is a DC capacitor discharging but beyond that I don’t know what components to check or how (other than one-way continuity of diodes, resistance of resistors, etc. I have completely eliminated the possibility that it’s a faulty connection or power cord.

1. If an atom loses one or more electrons, it becomes
A. negatively charged.
B. positively charged.
C. neutrally charged.
D. heavier than before.

2. A __________ is attracted to a positive charge.
A. positive charge
B. neutral charge
C. negative charge
D. nuclear charge

3. Electric force is
A. a force that may be transferred by friction, contact, or induction.
B. an excess or shortage of electrons or protons.
C. a property that causes subatomic particles to attract each other.
D. the repulsion or attraction between electrically charged objects.

4. The amount of charge that produces the field and the distance from the charge determine
A. the size of an electric force.
B. the strength of an electric force.
C. the brightness of an electric field.
D. the weight of an electric force.

5. Static discharge occurs when
A. a pathway through which charges move suddenly forms.
B. two electric charges come in contact with each other.
C. an excess or shortage of electrons occurs.
D. like charges repel and opposite charges attract.

6. Increasing the distance between two objects will
A. cause an excess number of electrons to be present.
B. increase the electric force between the objects.
C. reduce the electric force between the objects.
D. not change the electric force between the objects.

7. In a direct current, electric current flows
A. back and forth.
B. and regularly reverses direction.
C. in one or more directions.
D. only in one direction.

8. __________ is the continuous flow of electric charge.
A. Resistance
B. Electric current
C. A superconductor
D. Voltage

9. Electric current __________ through electrical conductors.
A. flows easily
B. encounters resistance
C. is insulated
D. does not flow

10. Alternating currents
A. cannot flow through conductors.
B. only move in one direction.
C. regularly reverse directions.
D. cannot be insulated.

11. All of the following are good insulators EXCEPT
A. Wood
B. Rubber
C. Copper
D. Plastic

12. Resistance is __________ to the flow of __________.
A. the opposition; protons
B. the opposition; electric charges
C. a conductor; electric charges
D. not related; electric charges

13. A wire must be connected in a loop that includes an energy source in order for
A. a charge to be stopped.
B. a proton to transfer.
C. a photon to form.
D. a charge to flow.

14. If current increases while resistance remains constant, voltage will
A. not change.
B. decrease.
C. increase.
D. be reduced by half.

15. If current decreases while resistance remains constant, the voltage will
A. not change.
B. decrease.
C. increase.
D. be reduced by half.

16. According to __________, a circuit’s __________ is equal to resistance multiplied by current.
A. the law of circuits; total current
B. the law of voltage; voltage
C. Ohm’s law; voltage
D. the law of voltage; charge

17. What voltage source converts chemical energy into electrical energy?
A. Battery
B. Multimeter
C. Flashlight switch
D. Insulators

18. A material’s thickness, length, and temperature affect the material’s
A. amplitude.
B. resistance.
C. conductivity.
D. insulation.

19. What happens if one element stops functioning in a parallel circuit?
A. Devices plugged into electrical outlets will not operate.
B. None of the elements will operate.
C. Only one element will still operate.
D. The rest of the elements will still operate.

20. In what type of circuit does the charge have only one path through which it flows?
A. Flowing circuit
B. Electromagnetic circuit
C. Series circuit
D. Parallel circuit

21. A __________ works when a wire in the center melts if too much current passes through it.
A. Fuse
B. Current blocker
C. Safety
D. Independent circuit

22. An analog signal is produced by
A. encoding information as a string of ones and zeros.
B. not changing the voltage or current in a circuit.
C. continuously changing the voltage or current in a circuit.
D. pulsing a current on and off.

23. A semiconductor is a __________ that conducts current only under certain conditions.
A. high-voltage liquid
B. a crystalline solid
C. diode
D. transistor

24. Vacuum tubes do all of the following EXCEPT
A. Turn a current on or off
B. Change alternating current into direct current
C. Act as a semiconductor
D. Increase the strength of a signal

25. Which of these technologies uses a digital electronic signal?
A. Digital video disc (DVD)
B. Audio cassette tape
C. Video cassette tape
D. AM radio

The design of an electronic circuit calls for a 100-ohm resistor and a 250-ohm resistor connected in series so that their resistances add. The components used aren't perfectly uniform so that the actual resistances vary independently according to Normal distributions. The resistance of 100-ohm resistors has mean 100 ohms and standard deviation 2.5 ohms, while that of 250-ohm resistors has mean 250 ohms and standard deviation 2.8 ohms.

What is the distribution of the total resistance of the two components in series?

What is the probability that the total resistance lies between 345 and 355 ohms? Show your work.

Any help appreciated. Thanks.

15. On a printed circuit board, electronic components will be mounted

A. from the substrate side of the board.
B. from the side of the board that contains the conducting paths.

C. from the foil side of the board.

D. from the side of the board that's covered with copper sheeting.

16. Which of the following statements about the measurement of electrical quantities is correct?

A. Resistance is measured in units called ohms.
B. Voltage is measured in units called amperes.

C. Electrical pressure is measured in units called watts.

D. Current is measured in units called volts.

I need help understanding Ohms law.

Here is what I have so far.
I = V/R.

I is the current in amperes.
V is the potential difference in volts.
and
R is a circuit parameter called the resistance (measured in ohms, also equivalent to volts per ampere).

I need help understanding Ohms, and Ohms Law, can you please help?

I know what Amperes are, 6.242 x 10 to the 18th power. Electrons. passing a given point in one second. Right?

I am self taught, I am teaching myself about Electricity and Magnetism.

I get my information from sources like, Wikipedia, YouTube, Yahoo Answers, and Google.

Seriously, I am teaching myself, so that I can fully understand, and then learn how to built circuits, so I can make cool and or useful things with electronics, I wanna be a better Electronic Engineer, and not just a Software Engineer.

Thanx

An electronic flash attachment for a camera produces a flash by using the energy stored in a 720 µF capacitor. Between flashes, the capacitor recharges through a resistor whose resistance is chosen so the capacitor recharges with a time constant of 3.0 s. Determine the value of the resistance.

electronic circuit board with ICs

A.exploded
B.flowchart
C.assembly
D.pictorial

a resistor with a color brands brown, red, red and silver will have a resistance of?

A.120 ohms
B. 1,200 ohms
C. 2,100 ohms
D. 6,400 ohms

I know how to start and all the basics, but then how do I declare the fractions and how to write the formula?

Write a program that finds the resistance of an electronic circuit with three parallel resistors resistor1, resistor2 and resistor3. The resistance can be computed using the following formula:

resistance = 1/((1/resistance1) + (1/resistance2) + (1/resistance3))

I use C++ visual….

many thanks!
videobobkart, thx for answering!! my problem is how to write the formula in c++ especially that it contains fractions…here is what I'vd done (I know it contains lots of errors):
#include<iostream>
void main()
{
int r1,r2,r3;
float r;
std::cout<<"enter a value for r1";
std::cin>>1>>/>>r1;
std::cout<<"enter a value for r2";
std::cin>>1>>/>>r2;
std::cout<<”enter a value for r3”;
std::cin>>1>>/>>r3;
r=1/((1/r1)+(1/r2)+(1/r3))
std::cout<<"resistance ="<<r;
}
oh and again I use Microsoft visual c++ 6.0
how do i declare the "fraction" sign?

1. When electric current is flowing in a circuit, if the voltage applied to the circuit is increased,

A. the resistance will increase.
B. the current will increase.
C. the resistance will decrease.
D. the current will decrease.

2. Which of the following information sources will not be directly affected by the Telecommunications Act of 1996?

A. Telephone services
B. The Internet
C. Newspaper publishing
D. Cable television

3. Porcelain, paper, glass, and rubber are all examples of electrical

A. conductors.
B. batteries.
C. insulators.
D. grounds.

4. A testing instrument that an electronics technician will connect to selected points inside a piece of electronic equipment and measure electrical values such as ohms, volts, and amperes is called

A. a signal generator.
B. a power supply.
C. an oscilloscope.
D. a multimeter.

In a circuit there is a 100 volt DC source, a 2 ohm
resistor in parallel with a 4 ohm resistor, and then those
resistors are in series with a 3 ohm resistor in parallel
with a 6 ohm resistor. The circuit is terminated in a load
whose value varies randomly between 10 and 20 ohms.

If the power dissipated in the 2 ohm resistor goes above 35
watts, the resistor will burn and its resistance will jump
from 2 ohms to 1000000 ohms.

Solve the circuit 100,000 times (using random values for the
load). During the 100,000 simulations, count the number of times that
the 2 ohm resistor burns up. Also, calculate the average
voltage delivered to the load resistor when the 2 ohm
resistor has burned up.

Your program should output only two numbers on separate lines
as follows:

1-Number of times that the 2 ohm resistor burns

2-Average voltage delivered to the load resistor calculated
over the cases where the 2 ohm resistor has burned up

The seed to use for the random number generator is 100000

I have no problem with the programming stuff, just the actual calculations.