# EC6401 Question Bank Electronic Circuits 2

EC6401 Question Bank Electronic Circuits 2 Regulation 2013 Anna University free download. Electronic Circuits 2 Question Bank free download.

## Sample EC6401 Question Bank:

1. What are the advantages and disadvantages of RC phase shift oscillators?[ APR/MAY 2008]

i. It is best suited for generating fixed frequency signals in the audio frequency range.
ii. It requires no transformer or inductor, hence less bulky.
iii. Simple Circuit.
*Pure sine wave output is possible.

i) It requires a high β transistor to overcome losses in the network.
ii) These oscillators are not suitable for high frequency operation.
iii) Frequency of oscillation can not be changed easily. To change the frequency of oscillation, the three capacitor or resistors should be changed simultaneously. This is inconvenient.

2. What is the necessary condition for a Wien bridge oscillator circuit to have sustained oscillations? [MAY/JUNE 2013]

Then for oscillations to occur in a Wien Bridge Oscillator circuit the following conditions must apply.

• With no input signal the Wien Bridge Oscillator produces output oscillations.
• The Wien Bridge Oscillator can produce a large range of frequencies.
• Voltage gain of the amplifier must be at least 3.
• The network can be used with a Non-inverting amplifier.
• Input resistance of the amplifier must be high compared to R so that the RC network is not overloaded and alter the required conditions.
• The output resistance of the amplifier must be low so that the effect of external loading is minimised.

3. Define piezoelectric effect.[MAY/JUNE 2006]

The piezo electric Crystals exhibit a property that if a mechanical stress is applied across one face the electric potential is developed across opposite face and viceversa. This phenomenon is called piezo electric effect.

4. What is the principle behind operation of a crystal oscillator?[NOV/DEC 2007]

The principle behind the operation of crystal is piezoelectric effect. According to this effect, if a mechanical stress is applied across one face the electric potential is developed across opposite face and viceversa.

 Subject Name Electronic Circuits 2 Subject Code EC6401 Regulation 2013