0
A transistor has three leads, called the base, the collector, and the emitter. The voltage of the base (in relation to the ground) determines whether and how much current flows from the collector to the emitter. An NPN transistor can be off, meaning that there is no (or very little) voltage from the base; partly on, meaning that there is some voltage from the base; or saturated, meaning that it is receiving full voltage from the base. A saturated transistor allows the current to flow from the collector to the emitter unopposed; a partly on transistor provides some resistance; and a transistor that is off provides full resistance. A PNP transistor is similar to an NPN transistor except it performs the opposite function: when it is saturated, the current is fully resisted; when there is no voltage from the base, the current is not at all resisted; and when it is partly on there is some resistance.
In sum, a transistor controls the flow between the collector and the emitter based upon the voltage of the base. this is carbage. a transistor is basicaly two diodes back to back base being common TO BOTH DIODES because of inpurity doping on purpose at the depletion region the transistor will control the current flow on the other diode. Once it reaches saturation both diodes conduct therefore current can flow in BOTH DIRECTIONS ACROSS IT.
Wiki User
∙ 15y ago
Wiki User
∙ 14y agoA resistor is a type of electronic part that slows the flow of electricity through an electronic circuit. This is used to allow large amounts of electricity to be switched and controlled by a switch that may use 1% of the electricity being controlled
Wiki User
∙ 15y agoA device used to control current in an electric circuit by providing resistance.
Wiki User
∙ 15y agoIt means to sister over again. . .
Add your answer:
Earn +20 pts
What is the concept of resistor tolerance and its importance?
Resistor tolerance is how accurate the resistor value is. You may have a 10% tolerance, 820 ohm resistor, which means the actual value of resistance is 820 ohms +/- 82 ohms. If you design a circuit that has very stringent requirements for resistor values, you may need to purchase a resistor that has a smaller tolerance (like 5, 2, 1, .5%). The smaller the tolerance, the more expensive it will be (generally).
Define zero ohm resistor.?
A zero-ohm resistor does not exist, so we are talking about an ideal resistor. An ideal resistor is needed for description in a circuit, where we lump all wire/parasitic resistances into discrete resistors, but the wire joining two discrete resistors is considered to have no resistance. My definition: a zero-ohm resistor is an ideal resistor that does not consume energy when a current exists in the resistor. Alternatively, a zero-ohm resistor is an ideal resistor that cannot sustain any potential drop when a current is on. Thirdly, a zero-ohm resistor is an ideal resistor that will conduct an infinite current when a voltage is applied across it.
Why do resistor voltage decrease while capacitor discharges?
The reason why resistor voltage decreases while a capacitor discharges is because the resistor acts like a source of electrical energy. As the capacitor discharges, it draws energy from the resistor, which causes the voltage across the resistor to decrease. This is because the capacitor is acting like a drain, and is taking energy out of the resistor, thus causing the voltage across the resistor to decrease. The resistor and capacitor work together in order to create a discharge circuit. This is done by connecting the capacitor to the resistor, and then to a voltage source. The voltage source supplies the energy to the resistor, and then the resistor transfers this energy to the capacitor. As the capacitor discharges, it takes energy from the resistor, which causes the voltage across the resistor to decrease. In order to understand this process better, it is important to understand the basics of Ohm's Law. Ohm's Law states that the voltage across a resistor is equal to the current through the resistor multiplied by the resistance. As the capacitor discharges, it takes energy from the resistor, which means that the current through the resistor decreases, and therefore the voltage across the resistor will also decrease.
What is the relationship between Wattage and resistance of resistor?
There is no direct relationship.Power ('wattage') is a measure of the rate at which the resistor can dissipate energy; excessive power means that a resistor cannot dissipate energy fast enough to prevent its temperature becoming excessive -excessive enough to damage the resistor.As the rate at which a resistor can dissipate energy is determined by its physical size, a resistor's power rating(maximum continuous power it can handle without exceeding its rated temperature) depends on the physical size of the resistor.On the other hand, the resistance of a resistor is notaffected by its physical dimensions, as a resistor can be manufactured to any particular value of resistance for whatever physical size is necessary to achieve its rated power.If you know a resistor's rated power and its resistance, then you can calculate the maximum continuous current that resistor can handle without overheating (using the equation: power = current squared x resistance).
Why resistor should disconnected from the circuit when measured the value of resistor?
if not disconnected you will measure the resistance of the circuit in parallel with the resistor.
Difference between variable and fixed resistor?
Variable resistors means that a resistor which can change its resistance by control by any person or it self and fixed resistor means that it can not change its value.
Does a variable resistor have a bias?
A variable resistor means that the resistance can be varied, usually by using a slide. A fixed resistor can not be varied.
When a manual refers to a particular resistor as 2.2 megohm resistor does this means the resistor can safely carry a current of 2200000 amperes?
No. It means it has a resistance of 2,200,000 Ohms. Plus or minus the tolerance.
On a resistor the first colored band means?
A: the first digit
What does k and the m stand for on a resistor value?
"k" means thousand "m" means million
What a weak pull up resistor?
A: That refers to a resistor pull up that is not sufficient to do the job that is to pull up. It also means is greater in value that it should be
What does 470R mean?
it means 470 resistor and is used in many circuit boards.
Diff between weak and strong pull up resistor?
A strong pullup means using small value resistor for pull up whereas a weak pullup means using high value resistor for pulling the signal to Vcc. A strong pullup reduces the RC time constant. Soumen C
What does 1 4W and 1 8W means for resistors and do they affect the value of the resistor?
It means the maximum power each one is capable of dissipating. The power dissipated by a resistor is (current through it)2 x (its resistance). If you exceed the power rating of a resistor, it will overheat, and that always increases its resistace value, at least for as long as it remains hot. If you take it to the extreme, the resistor can melt, smoke, crack, explode, etc. The power rating of a resistor has no direct effect on its resistance value.
What is the concept of resistor tolerance and its importance?
Resistor tolerance is how accurate the resistor value is. You may have a 10% tolerance, 820 ohm resistor, which means the actual value of resistance is 820 ohms +/- 82 ohms. If you design a circuit that has very stringent requirements for resistor values, you may need to purchase a resistor that has a smaller tolerance (like 5, 2, 1, .5%). The smaller the tolerance, the more expensive it will be (generally).
Define zero ohm resistor.?
A zero-ohm resistor does not exist, so we are talking about an ideal resistor. An ideal resistor is needed for description in a circuit, where we lump all wire/parasitic resistances into discrete resistors, but the wire joining two discrete resistors is considered to have no resistance. My definition: a zero-ohm resistor is an ideal resistor that does not consume energy when a current exists in the resistor. Alternatively, a zero-ohm resistor is an ideal resistor that cannot sustain any potential drop when a current is on. Thirdly, a zero-ohm resistor is an ideal resistor that will conduct an infinite current when a voltage is applied across it.
What is the function of the legs on a transistor?
as the name suggest transistor means to transfer resistor, it is an electronic device,
