Analog Circuit Technical Question & Answer
Q. In a LC filter the ripple factor-
Ans. Has the lowest value
Q. A dc-to-dc converter having an efficiency of 80% delivering 44W to a load. If converter is generating an output of 200V form an input of 20V then current drawn from the source will be-
Ans. 1.0 A
Q. Higher order active filters are used for variable-
Ans. Roll-off rate
Q. In order to obtain triangular pulses at the output of the circuit shown in the figure the input should be-
Q. The op-amp circuit shown in the given figure is a/an-
Ans. Low-pass circuit
Q. Half wave rectifier has theoretical maximum efficiency of-
Q. Full wave rectifier has theoretical maximum efficiency of-
Q. An ideal power supply has-
Ans. Zero internal resistance
Q. DC output drops from 50V with on load to 48 volt with full load. Percentage load regulation is-
Q. Excessive hum in a power supply is generally due to-
Q. The common collector amplifier is also called emitter follower because-
Ans. Emitter voltage follower the base signal voltage
Q. In IC amplifier-
Ans. Input and output signals are in phase
Q. A common base amplifier is so called because-
Ans. Base region is located between emitter and collector regions
Q. The input circuit of CB amplifier is-
Ans. Emitter-base circuit
Q. in a JEFT trans conductance gm is of the order-
Ans. 1 mS
Q. Presence of emitter circuit bypass capacitor adversely affects the-
Ans. Low frequency response
Q. In RC coupled amplifier the dc component is blocked by-
Ans. Coupling capacitor Cb
Q. Which of the following amplifiers produces the least distortion-
Ans. Class A
Q. Class A amplifier is used when-
Ans. No phase inversion is required
Q. In the output of a push pull amplifier the most disturbing harmonic distortion is-
Ans. Third harmonic
Q. Maximum theoretical collector circuit efficiency of class A series fed amplifier is-
Q. The maximum theoretical collector circuit efficiency of class B amplifier is-
Q. Compared to single ended amplifier a push pull amplifier offers-
Ans. Less distortion and more output power
Q. Crossover distortion ___________ takes place in-
Ans. Power amplifiers
Q. An oscillator is basically an amplifier with-
Ans. Infinite gain
Q. For good transient response the transfer function of the amplifier should not have-
Ans. Poles in the left half of the s-plane
Q. A different amplifier has a differential gain of 20,000. CMRR=80dB. The common mode gain is given by-
Q. In a feedback series regular circuit the output voltage is regulated by controlling-
Ans. Voltage drop across the series pass transistor
Q. A Hartley oscillator is used for the generation of-
Ans. Audio-frequency oscillation
Q. A personal computer has typically of main memory-
Ans. 256 kilobytes to 1 megabyte
Q. A p-n junction diode’s dynamic conductance is directly proportional to-
Ans. Its current
Q. As compared to a full wave rectifier using the diodes the four diode bridge rectifier has the dominant advantage of-
Ans. Blower peak increases voltage requirement
Q. The ideal characteristic of a stabilizer is constant-
Ans. Output voltage with low internal resistance
Q. The current range in a voltage regulator can be improved by-
Ans. Replacing the series transistor by a Darlington pair
Q. The function of a bleeder resistor in a rectifier with LC filter is to-
Ans. Maintain the minimum current is necessary for optimum inductor operation
Q. The circuit shown in the given figure is a/an-
Ans. High pass filter
Q. A trans conductance amplifier has-
Ans. High input and output impedance
Q. The primary advantage of a crystal oscillator is that-
Ans. Its frequency of oscillation remains almost constant
Q. In a transistor amplifier the reverse saturation current ICO–
Ans. Doubles for every 10deg C rise in temperature
Q. Wide banding technique is employed in the-
Ans. Video amplifier of a TV receiver
Q. Which one of the following power amplifiers has the maximum efficiency?
Ans. Class A
Q. The voltage gains of an amplifier without feedback and with negative feedback respectively are 100 and 20. The percentage of negative feedback would be-
Q. A 1 ms plus can be stretched to 1 s plus by using a/an-
Ans. Monostable multivibrator
Q. Population inversion in semiconductor laser diode is achieved by-
Ans. Heavily doping p and n sides
Q. The number of edges in a regular graph of degree D and N vertices is equal to-
Q. Which of the following data structure is used by a compiler to manage information about variables and their attributes?
Ans. Symbol table
Q. Why npn-transistor are preferred over pnp-transistor?
Ans. Mobility of majority carrier in npn-transistor is greater than the mobility of majority carrier in pnp-transistor
Q. Which one of the following statements is not correct with regard to power amplifiers?
Ans. They are used as the front end of multi-stage amplifier
Q. Which one of the following is a regulated power supply?
Ans. IC 723
Q. Which on of the following circuits is used for converting a sine wave into a square wave
Ans. Schmitt trigger
Q. Which one of the following type of negative feedback increases the input resistance and decreases the output resistance of an amplifier?
Ans. Voltage series feedback
Q. Which one of the following oscillators is well suited for the generation of wide range audio-frequency sine waves?
Ans. Wien-bridge oscillator
Q. Which of the following does not show non-liners V-I characteristics?
Ans. Thermistor at a fixed temperature
Q. Silicon diode are less suited for low voltage rectifier operation because-
Ans. Its cut in voltage is high
Q. Neutralizing capacitors are normally used in-
Ans. RF and IF amplifiers
Q. The figure given below shown the transfer characteristics of-
Ans. Peak clipper
Q. The figure shown below is a circuit of-
Ans. Voltage doubler
Q. In a practical oscillator circuit which one of the following limits the amplitude of the oscillations?
Ans. Onset of non-linearity
Q. The 3-dB cut off frequency of a d.c. amplifier is 5 MHz. what is its rise time?
Ans. 70 ns
Q. The rise time of an amplifier is-
Ans. Inversely proportional to the upper 3-dB frequency
Q. A power supply has a full-load voltage of 24V. what is its no-load voltage for 5% regulation (rounded to the nearest integer)?
Q. In a negative feedback amplifier the input impedance increased if the-
Ans. Feedback signal is a voltage
Q. A tuned amplifier has peak output at 2 MHz and quality factor 50. The bandwidth and 3-dB frequencies shall be at what values respectively?
Ans. 40 MHz, 2.04V, 1.96 MHz
Q. Operating point shift can occur in an amplifier due to-
Ans. Parasitic capacitance
Q. Cascade amplifier when compared with a simple common-emitter amplifier provide-
Ans. Same voltage gain but higher bandwidth
Q. In a class B push-pull operation the d.c. power drawn is 28W. what is the power delivered by the amplifier at the ideal maximum efficiency of power conversion?
Q. What is the advantage of a JEFT cascade amplifier?
Ans. High input impedance
Q. Where does the operating point of a class-B power amplifier lie?
Ans. Approximately at collector cut-off on both the d.c. and a.c. load lines
Q. The drain gats capacitance of a junction FET is 2 pF. Assuming a common source voltage gain of 20 what is the input capacitance due to miller effect?
Ans. 42 pF
Q. A transistor RC coupled amplifier is designed for a voltage and band gain of 20. But a measurement at a particular frequency shows the gain to be only 14. What is the likely phase shift at this frequency?
Q. In a biased JEFT the shape of the channel is as shown in the given figure because-
Ans. The drain end is more reverse biased than source end
Q. In a half-wave rectifier if an a.c. supply is 60 Hz than what is the a.c. ripple at output?
Ans. 60 Hz
Q. Pulses of definite width can be obtained from irregular shaped pulses-
Ans. When it is used as input to a Schmitt trigger
Q. Which one of the statement concerning IC fabrication is not correct?
Ans. A typical wafer of doped Si may be 400 mm thick of diameter 5-15cm. the purity of the wafer does not matter and can be even polycrystalline in nature.
Q. Which one of the following statements is not correct in respect of a series transistor feedback voltage regular?
Ans. Output resistance can be reduced by using a Darlington pair in place of the series transistor
Q. In a SSB transmitter one is most likely to find-
Ans. Class-B power amplifier
Q. Class AB operation is often used in power (large signal) amplifier in order to-
Ans. Overcome a cross-over distortion
Q. A triangular-square wave generator uses-
Ans. A differentiator and a compactor
Q. A amplifier has two identical cascaded stages. Each stage has bandwidth of 20KHz. The overall bandwidth shall approximately be equal to-
Ans. 12.9 KHz
Q. In a BJP amplifier with the introduction of feedback the input impedance is reduced output impedance is increased bandwidth is increased and distortion is reduced. The feedback is-
Ans. Current shunt
Q. An operational amplifier possesses-
Ans. Very large input resistance and very small output resistance