PUC Science 2nd PUC Class 12 - Karnataka Board PUC Important Questions for Physics

Explain briefly with the help of necessary diagrams, the  reverse biasing of a p-n junction diode. Also draw characteristic curves.

In the following diagram, is the junction diode forward biased or reverse biased ?

Write the functions of the three segments of a transistor.

The figure shows the input waveforms A and B for ‘AND’ gate. Draw the output waveform and write the truth table for this logic gate.

Explain the formation of depletion layer and potential barrier in a p−n junction.

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.

Identify the logic gate represented by the circuit as shown and write its truth table.

With the help of circuit diagram explain the working principle of a transistor amplifier as an oscillator.

Distinguish between a conductor, a semiconductor and an insulator on the basis of energy band diagrams.

The following figure shows the input waveforms (A, B) and the output waveform (Y) of a gate. Identify the gate, write its truth table and draw its logic symbol.

Draw a circuit diagram to study the input and output characteristics of an n-p-n transistor in its common emitter configuration. Draw the typical input and output characteristics.

Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.

How is a zener diode fabricated so as to make it a special purpose diode? Draw I-V characteristics of zener diode and explain the significance of breakdown voltage.

Explain briefly, with the help of a circuit diagram, how a p-n junction diode works as a half wave rectifier.

What will be the values of input A and B for the Boolean expression `overline ((A +B) .(A*B)) =1?`

Give two examples of communication system which use space wave mode.
A TV tower is 80 m tall. Calculate the maximum distance upto which the signal transmitted from the tower can be received.

By what percentage will the transmission ranges of TV tower be affected when the height of the tower is increased by 21%?

Why are high frequency carrier waves used for transmission?

What is meant by term ‘modulation’? Draw a block diagram of a simple modulator for obtaining an AM signal.

Why is frequency modulation preferred over amplitude modulation for transmission of music?