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CBSE Class 12-science Answered

(a) In the figure given below, the input waveform is converted into the output waveform by a device 'X'. Name the device and draw its circuit diagram.     (b) State how the oscillations are sustained in a transistor oscillator.
Asked by Topperlearning User | 01 Jul, 2014, 01:06: PM
answered-by-expert Expert Answer

(a) The device is Full wave rectifier.

Diagram of the full wave rectifier is:

 

(b)

In an oscillator, one gets sinusoidal output signal without any sinusoidal input signal. That is, essentially the output is self-sustained. To sustain the oscillation, a part of output is feedback to the input in phase with the starting power as shown in the figure. This type of feedback is called positive feedback. The feedback is achieved by inductive coupling (through mutual coupling) or LC networks. Such network is called feedback network. 

                                Fig: Feedback mechanism in the oscillator circuit

 

 

 

 

 

 

Answered by | 01 Jul, 2014, 03:06: PM

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