Duduli

Variation of current with bias voltage is called characteristic of pn junction. Forward biased pn junction is a low resistance instrument while reverse biased pn junction is a high resistance instrument.

It is defined as the voltage available at the output terminal of an op-amp when no input signal voltage is applied. For ideal op-amp output offset voltage is zero while for practical op-amp the output offset voltage is non-zero.    

Extrinsic semiconductor is formed when some impurities added to pure form of semiconductor. The process of increase in conductivity by adding some impurity in small amount is called doping. Extrinsic semiconductor will be obtain by adding trivalent or pentavalent element to Germanium crystal. Therefore extrinsic semiconductor can be classified into two categories                  1. N-type semiconductor                  2. P-type semiconductor 

It is defined as the frequency at which magnitude of high frequency voltage gain is equal to the 1/√2 of mid frequency voltage gain.

In a phase shift oscillator, a phase shift of 180⁰ is introduced due to the phase shift circuit. A further phase shift of 180⁰ is introduced due to the transistor properties. Thus, energy supplied back to the tank circuit is assured of correct phase.

It is defined as the range of frequency over which the voltage gain is equal to or greater than 1/√2 of mid frequency voltage gain.   

Root mean square (RMS) value of current is that value of steady current which produces same heating effect through load resistance in same time as is produce by AC in one of its cycle.

Forward current transfer ratio (α) for common base operation is defined as the ratio between change in collector current to the change in emitter current keeping collector base voltage constant.

In non inverting amplifier the input signal voltage is applied to the non inverting input terminal of op-amp & inverting terminal is grounded. A part of output signal voltage is fedback to the inverting input terminal of op-amp through fedback resistance.

It is defined as the ratio between output voltage to the input signal voltage.         A' = Vo/Vs  Where, A' = closed loop voltage gain               Vo = output voltage               Vs = input signal voltage 

It is defined as the ratio of output voltage to differential input voltage.          A=Vo/Vd Where, A  = open loop voltage gain             Vo = output voltage             Vd = differential input voltage 

The resistance offered by the diode to the reverse bias is known as reverse resistance. It can be d.c. reverse resistance or a.c. reverse resistance depending upon whether the reverse bias is direct or changing voltage. Ideally, the reverse resistance of a diode is infinite. However, in practice the reverse resistance is not infinite because for any value of reverse bias there does exist a small leakage current.

A zener diode can be used as a voltage regulator to provide a constant voltage from a source whose voltage may vary over sufficient range.

When the feedback signal which is fed back at input is out of phase with input, then feedback is called negative or degenerative feedback. Negative feedback decreases gain of amplifier.

In full wave bridge rectifier four diodes D1,D2,D3 & D4 are connected along four arms in the way similar to the resistances connected in wheat stone bridge.

The process of making operating point independent of temperature changes or variations in transistor parameters is known as transistor stabilization.

It is defined as maximum rate of change of output voltage. It is denoted by s(r).          s(r) = (dvo/dt)max Where, vo = output voltage

The circuit with which the waveform is shaped by removing (or clipping) a portion of the applied wave is known as a clipping circuit.

A filter circuit is a device which removes the a.c. component of rectifier output but allows the d.c. component to reach the load.

Common mode rejection ratio is defined as the ratio of differential input signal to the voltage gain for common mode input signal.