Analog Electronics
Positive feedback is mainly used in
Answer: D
In oscillators, the oscillations are generated due to positive feedback. In thyristors anode current increases due to positive feedback.
Enter details here
An ideal power supply has
Answer: A
An ideal power supply should have zero voltage drop.
Enter details here
The input voltage for starting oscillations in an oscillator is caused by
Answer: C
The amplifier in the oscillator amplifies the noise voltages. However phase shift around the closed loop is zero at only one frequency. Therefore, only this frequency appears at output.
Enter details here
An amplifier has a large ac input signal. The clipping occurs on both the peaks. The output voltage will be nearly a
Answer: B
When a sinusoidal voltage is clipped on both sides it resembles a square wave.
Enter details here
In a CE amplifier
Answer: B
Since ac collector resistance is less than dc collector resistance, slope of ac load line is more than that of dc load line.
Enter details here
The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be
Answer: D
It is 180° for purely resistive load and between 180° and 270° for R-L load.
Enter details here
The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.
Answer: B
Efficiency of full wave rectifier with centre tapped transformer is slightly higher than that of bridge rectifier.
Enter details here
DC amplifiers have a tendency to be unstable.
Answer: A
Due to drift.
Enter details here
The open loop gain of an amplifier is 200. If negative feedback with β = 0.2 is used, the closed loop gain will be
Answer: C
Closed loop gain = 
.
Enter details here
A bridge rectifier circuit has input of 50 Hz frequency. The load resistance is RL and filter capacitance is C. For good output wave shape, the time constant RLC should be at least equal to
Answer: D
Time constant RLC must be about 5 x 20 ms.
Enter details here
Topics
- Materials and Components
- Electromagnetic Field Theory
- Networks Analysis and Synthesis
- Measurements and Instrumentation
- Analog Electronics
- Automatic Control Systems
- Radio Receivers
- Satellite Communication
- Signals and Systems
- Exam Questions Papers
- Electronic Devices and Circuits
- Power Electronics
- Digital Electronics
- Communication Systems
- Microwave Communication
- Microprocessors
- Matching Questions