Saturday, May 28, 2011
Placement Preparation questions [SANKALP SEMICONDUCTORS]
1) State typical parameters of 741IC op-amp.
2) How does the non-inverting amplifier differ from voltage follower circuit?
3) What is meant by virtual ground or virtual earth?
4) Explain input bias current, output impedance and voltage gain?
5) State some typical op-amp packages.
6) Define input offset voltage and input offset current of op-amp.
7) Define common mode voltage, voltage gain, common mode rejection ratio and supply voltage rejection.
8) There are some limits in input and output voltage range of op-amp. When does it occur?
9) State typical op-amp slew rate.
10) How input offset voltage can be prepared by errors in bias resistors?
11) Compare the performance of a differential input output amplifier with that of a differential amplifier.
12) What are the different types of miscellaneous op-amp linear application referred to voltage and current sources?
13) Why are bipolar transistors used in low resistance voltage sources?
14) What is the main disadvantage in using a simple voltage source and what can be done to overcome it?
15) What is the difference between the current sources and current sinks with respect to transistor and MOSFET used?
16) What is the disadvantage of current amplifier attenuator?
17) In DC voltmeter, the load resistor is replaced by -------------- at op-amp ---------- terminal.
18) Design of a linear ohmmeter involves ------------- and ------------- circuits.
19) Which IC is used for integrated circuits instrumentation amplifier?
20) What is the expression of voltage gain in instrument amplifier circuit?
21) What is the difference in the current flow in full wave AC voltmeter and half wave AC voltmeter?
22) Why is Zener diode used in voltage sources?
23) What does most of the sinusoidal oscillators consist of?
24) What are the main components of triangular/rectangular wave generator?
25) Define duty cycle of pulse waveform.
26) What are the conditions to be fulfilled for oscillations to be sustained in any sinusoidal oscillator?
27) What is a Wein Bridge oscillator?
28) In Wein bridge oscillator, does the feedback network phase shift the output?
29) What is the use of op-amp in rectifier, clipping and clamping circuits?
30) Mention any two advantages of op-amp precision rectifier circuit over a simple diode rectifier.
31) Why is a precision full wave rectifier circuit also known as an 'absolute value circuit'?
32) What is a dead zone circuit?
33) What is the function of a peak detector?
34) What is a sample and hold circuit?
35) What is a differentiating circuit?
36) What is the relationship between capacitor C and current I?
37) What is the output voltage of a differentiator circuit?
38) What is an integrating circuit?
39) What is the output equation of an integrator?
40) What is the output of the differentiator when the input is triangular waveform?
41) Why are active filters also called frequency selective circuits?
42) Why active filters are preferred over passive filters?
43) Why Butterworth filter is called flat filter?
44) Can filter be designed as an amplifier with infinite gain?
45) How can active filter be used to correct harmonic components that cause neutral current in pc?
46) Why stop band gain for first order filter is 20dB?
47) For an ideal filter, what is the pass-band and stop-band loss?
48) In Butterworth filter, why there are ripples in stop-band and pass-band?
49) In Butterworth approximation which bands have ripples?
50) Which Error amplifier is used in DC-DC converter?
51) To compensate the PWM mode buck converter, which topology of the Error amplifier is better? Whether it is Gm-based (folded cascade) or voltage amplifier (two stage opamp)?
52) What are the disadvantages of subthreshold PMOS op-amp's?
53) What is the output if Vcc=5V,Vee=0 and input=some value for inverting and non-inverting op-amp?
54) What are the advantages and disadvantages of op-amp as dc amplifier?
55) What precautions can be taken to minimize effect of noise of an op-amp circuit?
56) What are the types of voltage regulators?
57) For what purpose voltage regulators are used?
58) What do you mean by ripple rejection in regulators and its unit?
59) What are the advantages of adjustable voltage regulators over fixed type?
60) What is the output voltage expression for LM317?
61) What are the roles of C1, C2 and C3 in LM317 adjustable voltage regulators?
62) What is the input voltage range for LM317?
63) What is the importance of external transistor and 1mH choke in switching regulator?
64) List four major components of switching regulator.
65) What is a voltage reference? Why is it needed?
66) What are the ac response characteristics of the op amp?
67) How dc level is produced in radio receiver system?
68) What is the role of coupling capacitor in ac amplifiers?
69) What is scaling ac amplifier?
70) Why the instrumentation amplifiers are intended?
71) Design a peaking amplifier circuit to provide a gain of 5 at a peak frequency of 10KHz.
72) Analyse the operation of an ac amplifiers
73) Calculate the BW and the maximum output voltage swing of a non inverting amplifier?
74) On what factor bandwidth of the amplifier depends?
75) How BW is related to figure of merit of peaking ac amplifiers?
76) What are non linear circuits?
77) Why input impedance is low in op-amp?
78) How many transistors are required to design the op-amp?
79) Non linear circuits are also called as __________
80) Importance of negative feedback in non linear op-amp circuits ________________
81) When BIFET op-amp is to be used in a crossing detector, capacitor value must be ___________
82) Monostable multi-vibrator is often called as _________
83) Pin description of 555 timer ___________
84) In monostable operation the time during the output remains high ____________
85) Slew rate is a function of ___________
86) Effect of slew rate ____________