Saved Bookmarks
| 1. |
Draw the circuit diagram of transistor as an oscillator and explain its working. |
|
Answer» Solution :An L-C circuit can be used to produce oscillations of desired frequency. It consists of a tank circuit consisting of inductor L and CAPACITOR C connected in parallel. The frequency of the tank circuit is given by `v=(1)/(2pisqrt(LC))` Due to the resistance of inductive coil, there occurs a small but CONSTANT energy loss and oscillations thus produced are damped. To transmit speech or MUSIC, we require undamped electromagnetic waves called carrier waves.  To do so an L-C circuit is coupled with transistor in such a way that there is a proper feedback to the L-C circuit at the proper timings so that the energy of L-C circuit remains the same throughout oscillaitons. When key K is pressed, the collector ATTAINS positive potential due to which a weak collector current will start rising in `L_(1)`. The increasing magnetic flux is linked with `L_(1)` and HENCE with L. |
|