Advertisements
Advertisements
Question
The amplifiers X, Y and Z are connected in series. If the voltage gains of X, Y and Z are 10, 20 and 30, respectively and the input signal is 1 mV peak value, then what is the output signal voltage (peak value)
- if dc supply voltage is 10V?
- if dc supply voltage is 5V?
Advertisements
Solution
Total voltage amplification is defined as the ratio of output signal voltage and input signal voltage.
According to the problem. voltage gain in X, vx = 10
Voltage gain in Y, vy = 20
Voltage gain in Z, vz = 30
ΔV1 = 1 mV = 10–3 V
And Total voltage amplification = vx × vy × vz
ΔV0 = vx × vy × vz × ΔV1
= 10 × 20 × 30 ×10–3 = 6V
- If DC supply voltage is 10 V, then output is 6 V, since the theoretical gain is equal to practical gain, i.e., the output can never be greater than 6 V.
- If DC supply voltage is 5 V, i.e., Vcc = 5 V. Then, the output peak will not exceed 5 V. Hence V0 = 5 V.
APPEARS IN
RELATED QUESTIONS
Colour of light emitted by LED depends upon__________________ .
- its forward bias
- its reverse bias
- the band gap of the material of semiconductor
- its size
With what considerations in view, a photodiode is fabricated? State its working with the help of a suitable diagram.
Even though the current in the forward bias is known to be more than in the reverse bias, yet the photodiode works in reverse bias. What is the reason?
Using the necessary circuit diagrams, show how the V-I characteristics of a p-n junction are obtained in
Forward biasing
How are these characteristics made use of in rectification?
State its any ‘two’ uses of photodiode.
Write briefly the important processes that occur during the formation of p−n junction. With the help of necessary diagrams, explain the term 'barrier potential'.
An ideal diode should pass a current freely in one direction and should stop it completely in the opposite direction. Which is closer to ideal-vacuum diode or a p-njunction diode?
Draw the V-I characteristics of an LED. State two advantages of LED lamps over convertional incandescent lamps.
Write the important considerations which are to be taken into account while fabricating a p-n junction diode to be used as a Light Emitting Diode (LED). What should be the order of the band gap of an LED, if it is required to emit light in the visible range? Draw a circuit diagram and explain its action.
Explain the three processes involved in the working of a solar cell.
What is the magnitude of the potential barrier across a Ge p-n junction?
Pressure P varies as P = `alpha/beta "exp" (- (alpha x)/"k"_"BT")`, where x denotes the distance, kB is the Boltzmann's constant, T is the absolute temperature and α and β are constant. The dimension of β is ______.
Which one of the following is not the advantage of LED?
Consider the following statements (A) and (B) and identify the correct answer.
- A Zener diode is connected in reverse bias when used as a voltage regulator.
- The potential barrier of the p-n junction lies between 0.1 V to 0.3 V.
Briefly explain how emf is generated in a solar cell.
What energy conversion takes place in a solar cell?
Identify the special purpose diodes 'A', 'B' and 'C' from the given symbols.

Select the wrong statement in the case of LED.
