Electronics Engineering

shut up , if u ask that it is just weird : ( Kreep !

1

Depending upon the cell itself, it could be as simple as two dots on the back of the cell, which is the non-blue side. On other cells, it could be the white vertical lines on the front = negative and the dots on the back = positive.

No.

A: actually any active components will oscillate with positive feedback

A transistor can be used as an amplifier along with an LC tank circuit to form an oscillator; it is an active device (as LIBURNO states) which will amplify the feedback signal coming out of the LC tank circuit. The tank circuit has a natural resonant frequency, meaning the L and C together will try to generate a specific frequency; this is then fed back into the input of the transistor amplifier, and the output is fed to the LC tank circuit exacerbating this oscillation until it reaches its' maximum level.

An inverting amplifier can be used similarly; the output is fed to the input; this will cause the output to change as fast as the amplifier can. The frequency of this design is much harder to control, but potentially higher. Also, without the LC tank, the output voltage will remain lower.

V = I x R so current I = 1/2 amp. I bet the bulb is rated at 60 W because Watts = Current x Voltage.

Where V = voltage (volt)

I = current (ampere)

R = resistance (ohm)

Your question isn't easy to answer. A lamp has two 'resistances': a 'cold' resistance, and a 'hot' resistance. Before it is energised, it is cold, so its resistance is low; when it is energised, it becomes very hot, and its resistance increases significantly. So, the question is whether your '240 ohms' is the cold resistance or the hot resistance. If it is the cold resistance, then a current of 0.5 A will flow through it for a fraction of a second, then its resistance will increase significantly, and the current will fall to a very much smaller value.

An article for a magazine that is meant to tell people about how products are sold to different countries

Logic gates are in fact the building block of digital electronics; they are formed by the combination of transistors (either BJT or MOSFET) to realize some digital operations (like logical OR, AND, INVERT ). Every digital product, like computers, mobile, calculators even digital watches, contain logic gates. The use of logic gates in digital world can be understood better by the following example: the single bit full adder in digital electronics is a logic circuit which perform the logical addition of two single bit binary numbers (a,b,cin) a and b are the the two binary number of single digit (either 1 or 0) and cin is the carry input . say for example a,b,cin= 1,1,1 gave an logical sum output of 1 and a carry of 1 , a,b,cin= 110 gave sum= 0 and carry of 1. Now this adder can be formed by the combination of many gate like by using NAND gates only. or by using XOR , AND ,OR gates and so on. So, in a nutshell, the adder which is of great importance in your computer processor and also in many more applications is basically built from the logic gates.

Doppler radar is used to measure speed, not temperature.

That depends on the exact circumstances. For example, in electrical circuits, power = I2R. However, since the current, in turn, depends on the voltage and the resistance, it is better to express this as V2/R. For mechanical energy, power is basically speed times force.

The difference between a conductor and a insulator is that a conductor tries to keep the warmness away and the insulator tries to keep the warmness in. An insulator is like an refrigerator, and mabey a cooler so when you go hiking it keeps the coolness inside or keeps the warmness inside!!:-)<3

1. either field effect (JFET, MOSFET) or junction (BJT) or point contact (usually considered obsolete)
2. either small signal or high power
3. either electron majority carrier (N-channel FET, NPN BJT) or hole majority carrier (P-channel FET, PNP BJT)
4. either linear (used in amplifier and oscillator circuits) or switching (used in digital logic circuits)
5. etc.

You do not build a series circuit in your home. The only series circuits are the circuits that go through circuit breakers, light switches, and relays. Electrical and electronic devices use internal series circuits but those are the only ones people build. No one builds series circuits for house wiring. Electrical outlets are connected with parallel wiring.

If they're connected one at a time ... first one and then the other ... then each one has 120 volts
across it while it's connected to the supply.

If they're connected across the supply at the same time in parallel, then of course they have the
same voltage across them, because their ends are common.

If they're connected across the supply in series, then the voltage across the 50-ohm load is 40 volts,
and the voltage across the 100-ohm load is 80 volts.

Lower noise, higher gain.

A1: The output impedance of a power amplifier is always less than 0.1 ohms. There are no 4 ohm amplifiers on the market!

A2: I actually just bought a new car radio/CD player that specifically shows 4 ohm speakers on the sticker. It is designed to work optimally with 4 ohm speakers. If you use 8 ohm instead, it will work, but you will not get the full power output that is specified. The amp can only kick out so much voltage and so much amperage - if it is designed for 4 ohm speakers, and 200 watts (stereo, so 100 watts per speaker), it can supply 20 volts (P = V^2 / R). If you used 8 ohm speakers to this amplifier, each speaker would only get 50 watts powered at full output voltage.

Alternatively, if it is designed for 8 ohm speakers and 100 watts per speaker, it can provide 40 volts. If you used 4 ohm speakers instead, each speaker could be given 200 watts at 40 volts, resulting in severe overheating and damage to the amplifier.

capacitors can be used for many thing they are one of the most common electrical components they limit current differently at different frequency the higher the frequency the lower resistance. They can also be used to store voltage or build it up to be released all at once in a larger but than could be achieved other wise.

The generation of AC currents and relationship to frequency has to do with the speed of the unit that is turning the generator (prime mover).

The formula for frequency is f = Number of revolutions per minute of the engine (N) x Number of magnetic poles (P) / 120

Speed the prime mover up for a higher frequency, slow the prime mover down for a lower frequency. This is why the generator has to be wound for the voltage that it is going to produce and the frequency that it is to operate on.

This has probably got to do with Iron.

Most transformers consist of large amounts of iron that need time in order to change polarity of a magnetic field.

Faster frequency would make the transformer less efficient. The iron would not manage to become fully magnetized. Slower frequency would make the transformer need more iron, hence becoming heavier. If the size of the iron core were the same and we just lowered the frequency, then as soon as the magnetic field is buildt up, then the rest of the energy until next half wave will be transferred into heat.

It is simply a trade off between efficiency and practicality.

Today's high speed transformers operate at speeds between 20-80 Khz and is only doable due to a special core material of powdered iron that is much easier to magnetize.

Electricity in the early days was DC only. However, some decisions were made to use AC because DC is, at high voltages, very dangerous to humans, something that was demonstrated during the first few 'victims' of the electric chair that in the beginning operated at DC current only.

III LM324 Non-inverting AC Amplifier Circuit

R1 and R2 form a 1/2V+ voltage divider circuit, which biases the op-amp through R3. The circuit input resistance is R3, and the resistance of R4 ranges from several thousand ohms to tens of thousands of ohms.

Strangely there is two directions it is said to flow. The first and wrong is conventional current that is positive to negative. WRONG. Several hundred years ago people guest Electron current is the direction it actually goes in. This is negative to positive.

You'd potentially damage the meter. Whether you do or not is immaterial; if the meter cannot measure the range of voltages you are expecting, it will not give accurate readings over that voltage range, thus you should not use it. Buy a different meter that will measure over that voltage range, or use a voltage divider circuit to get a lower voltage at a certain ratio of what is actually in the circuit (this may be difficult to do, or very simple depending on the circuit tested - the key is you do not want to load the circuit with the voltage divider network).

If all the bulbs are connected in parallel, and there is enough current, yes, the brightness will be the same. The voltage (which is the amount of energy in every charge), remains the same for all bulbs

The formula you are looking for is I = E/R. Amps = Volts/Resistance.

If you say it is normally a 2 Amp circuit, it normally draws 2 amps.

Therefore the original resistance offered to the 12v battery is 2/12 = 6 Ohms.

If you then connect a 12 Ohm resistor in series, they are added, so R = 18 Ohms.

Now if you put 12v across this circuit it will draw 12/18 = 0.66 Amps.

Or

If you just put a 12 Ohm resistor across the 12v supply it will draw 1 Amp.

If the circuit is protected by a 2 Amp fuse, it will not blow, but the resistor will get hot.