why input impedance of bjt is low?
319515
This means that a small signal voltage variation at the input of the transistor produces a large emitter current variation. This shown that the input resistance of a transistor is low. ... Due to it a very large change in collector voltage shows only a small change in the collector current.
946542
A transistor acts as an amplifier by raising the strength of a weak signal. The DC bias voltage applied to the emitter base junction, makes it remain in forward biased condition. ... Thus a small input voltage results in a large output voltage, which shows that the transistor works as an amplifier.
1295083
For improving the CMRR of the differential Amplifier using opamp, u need to match all the ressistors in the differential Amplifier to around 0.1%, becauuse 10% mismatch in resistors causes 1/5th of common mode voltage to be appeared as differential voltage, which will be amplified and appears as output noise, or go for ...
1136162
It has been observed that the transistors in the native substrate tend to have better characteristics than that was made in a well. Because p devices inherently have lower gain than devices, n well process amplifies this difference while a p-well process moderates the difference.
1401673
A transistor acts as an amplifier by raising the strength of a weak signal. The DC bias voltage applied to the emitter base junction, makes it remain in forward biased condition. ... The low resistance in input circuit, lets any small change in input signal to result in an appreciable change in the output.
51831
Since impedance is a measure of how much the speaker resists current, the lower the impedance in ohms, the more power the speaker will draw from your receiver. Because of that, a 4 ohm speaker is considered more “power hungry” and will tax your amp more than a 6 or 8 ohm speaker.
501188
As MM cartridges have a higher output, they also have a higher impedance of 47,000 Ohms. In contrast, MC cartridges at lower outputs, have a lower impedance at 100 Ohms. For the capacitance, you'll find MM preamps with up to 100 pF while MC preamps have about 3000 pF.
176084
Resistance is simply defined as the opposition to the flow of electric current in the circuit. Impedance is opposition to the flow of AC current because of any three components that is resistive, inductive or capacitive. It is a combination of both resistance and reactance in a circuit.
1418853
Two 16 Ohm speakers wired in parallel results in a nominal 8 Ohm impedance. I say nominal because no moving coil driver maintains a fixed impedance. Driver impedance changes with frequency. Make sure driver polarity are the same (+ connected to +, — connected to —).
290943
Noise margins for CMOS chips are usually much greater than those for TTL because the VOH min is closer to the power supply voltage and VOL max is closer to zero. Real digital inverters do not instantaneously switch from a logic high (1) to a logic low (0), there is some capacitance.
1321629
A bipolar NPN transistor has a DC current gain, (Beta) value of 200. ... Also, there is a voltage drop between the Base and the Emitter terminal of about 0.7V (one diode volt drop) for silicon devices as the input characteristics of an NPN Transistor are of a forward biased diode.
573743
MOSFET is used for POWER SUPPLIES and is efficient. whereas BJT is used in low power consuming devices like LED. BJT consumes more power as it is a current controlled device,it results in less efficient than mosfet. ... MOSFET is efficient because its output depends on the input voltage and not input current.
134040
It's also important that the wire lengths to both speakers are the same to ensure they both have equal impedance values. ... The thicker a wire or the lower the gauge, the less resistance. It is therefore a combination between speaker impedance, length and gauge that affects the resistance.
976236
High impedance circuits are low current and potentially high voltage, whereas low impedance circuits are the opposite (low voltage and potentially high current).
1005991
As the Emitter of the UJT is connected to the capacitor, when the charging voltage Vc across the capacitor becomes greater than the diode volt drop value, the p-n junction behaves as a normal diode and becomes forward biased triggering the UJT into conduction. The unijunction transistor is “ON”.
1355280
So in one case a moving charge (current) and in other static charge (voltage) controls the output. This happens because in BJT the Base-Emitter junction conducts the charge of control current.
1436409
The BJT is a bipolar junction transistor whereas MOSFET is a metal oxide semiconductor field-effect transistor. ... BJT's are used for low current applications, whereas MOSFET is used for high power applications. Nowadays, in analog and digital circuits, MOSFETs are treated to be more commonly used than BJTS.