A 9.1 V battery is connected to a 6.2 pF parallel-plate capacitor. What is the magnitude of the charge on each plate?

Two devices with capacitances of 21.6 µF and 5.2 µF are each charged with separate 120 V power supplies. Calculate the total energy stored in the two capacitors.

The operating potential difference of a light bulb is 120 V. The power rating of the bulb is 45 W.

(a) Find the current in the bulb.
1 A
(b) Find the bulb’s resistance.
2

A circular parallel-plate capacitor with a spacing of 1.5 mm is charged to produce a uniform electric field with a strength of 3.2 106 N/C. What plate radius is required if the stored charge is -11.9 µC?
1 m

An electronic flash fires a blast of energy from a 804 µF capacitor into a xenon lamp. It recharges through a series resistor of 4.9 k. How long will it take to recharge 63% of its maximum charge?
1 s

A charged 603 µF capacitor is in series with an open switch and a 3.6 k resistor. If the switch is closed, how long will it take for the charge on the capacitor to decay down to 37% of its original value?
1 s

A resistor is placed in series with an uncharged 2.2 µF capacitor, and a 15.0 V battery is put across the two. If the current that immediately flows around the circuit is measured to be 10 µA, determine the resistance. What is the time constant of the circuit?
1 s

7. What is the total resistance of a circuit that contains two 100 Ω resistors connected in parallel? A. 10 Ω C. 50 Ω
B. 30 Ω D. 150 Ω 8. Which of the following is the correct Ohm’s law formula used to find current?A. l=R-E B.l=E-Rl C.l=E=R D.l=PR 10. If the voltage in a circuit is 24 V and the current is 2 A, what is the total power in the circuit?
A. 6 W C. 72 W
B. 48 W D. 102 W 11. What does the abbreviation VOM stand for?
A. volt-ohm-megohm C. volume-ohm-microamp
B. volt-ohm-milliammeter D. volume-origin-megohm14. What is the total power in a circuit with a current of 4 A and a resistance of 12 Ω?
A. 4 W C. 48 W
B. 16 W D. 192 W

A fuse is a device designed to break a circuit, usually by melting when the current exceeds a certain value. Fuses are widely used in electronic equipment, but have been replaced by circuit breakers in household wiring. In the "old days" people would sometimes replace a blown fuse with a penny, which happened to be the same size as a fuse. Was this a safe practice? Why

High-voltage power supplies are sometimes designed to have a rather large internal resistance as a safety precaution. Why is such a power supply with a large internal resistance safer than one with the same voltage, but lower internal resistance?

Can all combinations of resistors be reduced to series and parallel combinations?

Old-time Christmas tree lights had the property that, when one bulb burned out, all the lights went out. How are these lights connected, in series or in parallel? How could you rewire them to prevent all the lights from going out when one of them burned out?

Trying to follow seris then parallel and back is confusing. Any help on line(utube type sites) or really good books?

in electronic circuits

imagine a couple of led connected in series …..which drop 2 v across each led when forward biased…….so in total both of them drop 4 v …..now if a 400 ohm resistor is connected in parallel to this arrangment of 2 led ………and the whole is connected in series to a 600 ohm resistor…..now imagine the whole circuit is supplied by 10 v supply such that the leds are forward biased ………….now …if you calculated you will find since there is a drop of 4v across the led the drop accros the parallel 400 ohm must also be 4 v ……..so a current of 10 mA flows through the 400 ohm ……..and since the parallel arrangement drops 4 v we have 6v drop across the 600 ohm ,……so on calculatin the current we again get 10 mA……………does this mean …will the whole of 10 mA current will flow through 400 ohm or not ……..how does it split up in the parallel arrangement ….will the led light or not ………

Audio book is a plus, must cover all this topic.
Kirchhoff’s and Ohm’s Laws
Series Circuits
Parallel Circuits
Series and Parallel Combination
Alternating Current
Capacitive Reactance
Inductive Reactance
Resonance
Filters
Diodes
Transistors
Transistor Regulated Power Supply
Transistor Amplifiers
Differential Amplifiers
Operational Amplifiers

Maybe even with different materials, or semiconductor styles, in different parts, and other compound shapes, and materials for electronic components?
Example: On the surface of circuit board, etch a twin spiral, with two conductors running parallel to each other as they spiral toward the center, with a solder hole at its’ end, or at a location in it, so they could be connected to make parallel induction coils, with or without an inner end connection and with or without a center tap, at the same time (with who knows, what types, or how many possible uses), or left separate to make a capacitor, or used as two parallel inductors, which would probably work and behave like a tank circuit, and could be adjusted by how the lines are spaced, and by how many time each is wound, or maybe even a type of antenna, or set of antennas.

Or make a coiled wire, and then, coil the coiled wire, or wind the coiled, coiled wire again, around a core, or center tap, another wire, or any other arrangement(s) – basically letting the mind keep wondering, and keep testing and calculating…..

Want more?
Have they ever tried standard material and/or other material, induction cores, made with open ends, closed at one, or at both, tapped in different ways, spiraled in different shapes (circular, triangular, etc…), or coated with molded plastic, at different thicknesses, etc, etc….?
Since there will always be new things, these shape ponderings might lead to some wiled stuff!!!

To me, learning from a book is basically memorizing what is already known, but real learning happens when your imagination kicks-in!

Thanks for thinking/pondering with me, and I hope it gets and keeps you wondering too!!!

How does an atom become positively charged?
A. The atom gains one or more protons.
B. The atom loses one or more protons.
C. The atom gains one or more electrons.
D. The atom loses one or more electrons.

A negative charge will attract
A. another negative charge.
B. a positive charge.
C. a positive or negative charge.
D. a neutral charge.

The repulsion or attraction between electrically charged objects is a(n)
A. electric charge.
B. electric force.
C. friction.
D. discharge.

What determines the strength of an electric force?
A. The size of the object in the electric field.
B. How many electrons are contained within the atom.
C. The amount of charge that produces the field and the distance from the charge.
D. How close the object is to the charge.

When a pathway through which charges can move forms suddenly, __________ occurs.
A. friction
B. contact
C. static discharge
D. induction

How can the electric force between two objects be reduced?
A. Increase the distance
B. Decrease the distance
C. Increase the charge
D. Reduce friction

In which type of electric current does charge flow in only one direction?
A. Alternating current
B. Rotating current
C. Direct current
D. Straight current

Electric current is the continuous flow of
A. electric charge.
B. electric resistance.
C. protons and neutrons.
D. electric voltage.

Electric current flows easily through materials known as
A. electrical insulators.
B. electrical conductors.
C. electrical resistors.
D. electrical current boosters.

In which type of current does electric charge regularly reverse its direction?
A. Alternating current
B. Switching current
C. Reversing current
D. Direct current

Electric current does NOT flow easily through insulators. Which of the following is an example of a good electrical insulator?
A. Battery acid
B. Copper wire
C. A silver spoon
D. Air

____________is the opposition to the flow of electric charges
A. resistance
B. insulation
C. induction
D. voltage

What is necessary for a charge to flow?
A. The wire must have an energy source at one end.
B. The wire must be connected in a loop that includes an energy source.
C. Potential difference of 0.
D. The wire must be connected in a loop.

According to Ohm’s law, what happens if voltage is increased?
A. The resistance is increased
B. The resistance is decreased
C. The current is increased
D. The current is decreased

According to Ohm’s law, if voltage is maintained and resistance is increased, what happens to the current?
A. The current is not affected
B. The current doubles
C. The current is increased
D. The current is decreased

According to Ohm’s law, a circuit’s voltage is equal to
A. current multiplied by charge.
B. resistance multiplied by current.
C. resistance multiplied by charge.
D. induction multiplied by current.

A battery is a voltage source that converts __________ energy to __________ energy.
A. chemical; electrical
B. electrical; chemical
C. chemical; potential
D. electrical; potential

What affects a material’s resistance, therefore changing the current?
A. Thickness, length, and composition
B. Temperature and insulation
C. Thickness, length, and temperature
D. Composition, temperature, and current

What type of circuit has two or more paths through which charges can flow?
A. Parallel
B. Series
C. Multiple series
D. Multiple parallel

What happens if one element in a series circuit stops functioning?
A. All of the elements have limited ability to operate.
B. All of the elements in line before the non-functional one can operate.
C. All of the elements can operate.
D. None of the elements can operate.

How does a fuse work?
A. Transfers extra charge to the earth
B. Prevents too much current from passing
C. A wire in the center melts if too much current passes through it
D. A switch opens when current is too high

What is produced by continuously changing the voltage or current in a circuit?
A. Direct current
B. Analog signal
C. Alternating current
D. Digital signal

Which device uses a crystalline solid to control current?
A. Vacuum tube
B. Super conductor
C. Semiconductor
D. Solid-state component

Vacuum tubes such as cathode-ray tubes (CRT) used in some computer monitors and televisions
A. can change alternating current into direct current.
B. can decrease the strength of an electronic signal.
C. never need to be replaced.
D. produce a digital signal of 1’s and 0’s.

DVD technology uses an electronic signal called a(n)
A. analog signal.
B. high-definition signal.
C. vacuum signal.
D. digital signal.