JNTUH BITS
SECTION-I: Multiple choice questions
1. Bootstrap’s sweep circuit produces _____ type of waveform. [ a]
(a) positive going Ramp (b) negative going Ramp (c) either a or b (d) Both a and b
2. The gate signal is also called as ___________. [c ]
(a) enabling pulse (b) control pulse (c) both a and b (d) either a or b
3. Sampling gates are used in _______. [d]
(a)Multiplexers (b) D to A converters (c) Sample and Hold circuits (d) All the above
4. The variations in phase delay occur due to ____. [c ]
(a) variations in loop gain (b) variations in supply voltage (c) both a and b (d) None
5. Among the logic families, low power dissipation is in _____. [ b]
(a)DTL (b) CMOS (c) TTL (d) ECL
6. Synchronization is said to be with frequency division, if the generators operate at___ [b ]
(a) same frequency (b) different frequency (c) both a and b (d) None
7. Synchronization with symmetrical signals is possible if_______. [c ]
(a) Tp <= T0 (b) Tp >= T0 (c) both a and b (d) either a or b
8. Which of the following logic family has highest fan-out. [ d]
(a) ECL (b) TTL (c) DTL (d) CMOS
9. Among the logic families, Slowest logic family is_____. [c ]
(a)TTL (b)DTL (c)CMOS (d)ECL
10. In Miller circuit, the gain A of the inverting amplifier should be ____. [c ]
(a) unity (b) zero (c) infinite (d) None of the above
11. The time during which the waveform returns to the initial value is called: [b ]
(a) fall time (b) flyback time (c) rise time (d) delay time
12. The circuit which require an amplifier whose gain is nearly infinity [b]
a) Boot strap ckt b) Miller ckt c) Phantastron ckt d) Inductor ckt
13. When generators with equal frequencies run in synchronism, the synchronization is said to be on a [ a]
a) one-to-one basis b) one-to-two basis c) two-to-one basis d) one-to-four basis
14. A Transmission circuit which allows an input Signal to pass through it during a selected interval and blocks it passage outside this time interval is called: [ a]
a) sampling gates b) conventional gates c) non-conventional gates d) logic gates
15. In unidirectional sampling gate the combination of RC forms a [ b]
a)Differentiator b) Integrator c) Coupling elements d) Multivibrator
16. The ratio of maximum deviation to the sweep amplitude is called [ b]
a) Slope error (b) displacement error (c) Transmission error (d) Linear error
17. A capacitor is charged linearly from a constant current source is used to generate [c ]
a)sine wave form (b) pulse wave form (c) time base waveform (d) trapezoidal wave form
18. The several factors which affect phase delay given rise to [ a]
a) Phase jitter b)amplitude jitter c)both amplitude and phase jitter d)frequency jitter
19. The interval of time is selected by means of an externally applied signal termed as:
[b ]
a) Transient signal b) gating signal c) output signal d)exponential signal
20. Logic gates are the basic elements that make a [ d]
a) analog system b) gating system c) basic system d)digital system
21.The relation between the slope error, displacement error and transmission error is
22. To get a saw-tooth out put waveform, the restoration time is [ a]
( a ) zero ( b ) rise time ( c ) storage time ( d ) infinity
23. In Miller time base generator, which of the following is used [b ]
(a) an inverting amplifier with a gain of unity (b) an inverting amplifier with a gain of infinity (c) non-inverting amplifier with a gain of unity (d) non-inverting amplifier with a gain of infinity
24. Synchronization with symmetrical signals is possible for [ d]
( a ) Tp = To only ( b ) Tp<To only ( c ) Tp >To only ( d ) both Tp<To and Tp> To
25. The time during which the output increases linearly is called [ a]
( a ) sweep time ( b ) flyback time ( c ) return time ( d ) restoration time
26. The interval of time of transmission of a signal in a sampling gate is selected by means of [ c]
( a ) time delay ( b ) off time of gate ( c ) gating signal ( d ) source signal
27. The following all are disadvantages of unidirectional gate, except [d ]
( a ) interaction between the signal source and control voltage source ( b ) limited used of gate ( c ) slow rise of the control voltage ( d ) little time delay though the gate
28. Which of the following logic gives the complementary outputs? [ d]
( a ) DTL ( b ) RTL ( c ) TTL ( d ) ECL
29. The voltage at the input of a gate which causes a change in the state of the ouput from one logic level to the other is [c ]
( a ) cut-in voltage ( b ) cut-off voltage ( c ) threshold voltage ( d ) peak voltage
30. The high state fan out of a gate is defined at when the [ c]
( a ) input is at logic ‘0’ ( b ) input is at logic ‘1’
( c ) output is at logic ‘1’ ( d ) output is at logic ‘0’
SECTION-II: Fill in the blanks
1. The ratio of the difference between the input and the output to the input at the end of the sweep time is called Transmission error
2. The output of the time base generator is called Sweep Voltage
3. The gain of a sampling gate is defined as The ratio of the output voltage to the input voltage during transmission
4. Ideal sampling gate is a transmission circuit in which the output is an exact replica of input waveform during a selected time interval and is zero otherwise.
5. The periodic variations in the phase delay are called Phase jitter
6. The range of synchronization increases with increasing sync signal amplitude
7. The relation between slope error and transmission error is es=2et
8. Typical noise margin for DTL family is 700mv
9. CML is also called as ECL
10. In a 4-diode sampling gate, minimum value of Vc is given by Vcmin=Vs [2+Rc / RL]
11.The maximum number of gates that can be driven by any logic gate is called Fan out
12) If synchronization is achieved with different frequencies, i.e one frequency being n times the other, then it is termed synchronization with frequency division
13) Two or more generators are said to be running synchronously if all of them arrive at some point in the cycle at exactly the same instant of time.
14) Sampling gates are used in chopper amplifiers
15) In positive logic system, the higher of the two voltage levels represent logic 1 and lower logic is 0
16) A voltage time base generator is one that provides an output voltage waveform a portion of which exhibits a linear portion with time
17) The ratio of the difference in slope at beginning and end of the sweep to initial value of slope is called slope error or sweep speed error
18) Sampling gates are classified into two types
19) Chopper often called as modulator
20) A positive logic NOR gate is equivalent to negative logic NAND gate
21).The time required by the sweep voltage to return to the initial value is called
restoration time, return time or flyback time
22. Compensating networks used to improve the linearity of bootstrap circuit
23. The output of a time-base generator is called sweep voltage
24. The range of synchronization decreases with decreasing of sync signal amplitude
25. When generator with equal frequencies run in synchronism, the synchronization is said to be on a one to one basis
26. Bidirectional sampling gates transmit signals in both the polarities
27. The sampling gate is used in sampling scope because the display consists ofsamples of input waveform
28. The power required by the gate to operated with 50% duty cycle at a specified frequency is called power dissipation
29. High state nose margin of a gate is defined as VOH(min)-VIH(min)
30. The basic TTL gate is NAND gate
PDC
UNIT-1(Linear wave shaping)
1. The waveform which preserves its form when transmitted through a linear network is a
___________. [ b ]
( a)Sine wave (b) Step signal (c) impulse signal (d) ramp signal
2. An RC high pass circuit has R= 1kΩ and C=0.5 μF. Its lower cutoff frequency is [ b]
(a) zero (b) 318.3 Hz (c) 1kHz (d) infinity
3. For a integrator, if input is square wave then the output waveform is _____ [ a]
(a) Impulse (b) Sawtooth wave (c) Triangular wave (d) Both a and c
4. A ringing circuit has a quality factor Q=24. This circuit will ring for how many number of cycles? [ c]
(a) 24 (b) 12 (c) 8 (d) 6
5. The rise time of the output of a low pass RC circuit is given by [c ]
(a) 2.2 RC (b) 0.35/fH (c) 2.2τ (d) all the above
6. What is the response of step input to a high pass RC circuit [ a ]
a) V e-t/RC b) V (1- et/RC) c) V et/RC d) V(1- e-t/RC )
7. When RC high pass circuit act as a differentiator? [ a]
a) RC<<T b) RC>>T c)RC=T d)RC=0
8. What is the name of the circuit which converts square wave in to spikes [ c]
a) Low pass RC b) Bi stable multi c) High pass RC d) Monoshot
section II: fill in the blanks:
9. For DC input signal capacitor C acts as a open circuit
10. The average value of the output value of an RC high pass circuit is Zero
11. In RC integrator circuit the output is taken across capacitor
12. ————-is the condition for an RC high pass circuit to acts as a differentiator.
13. Time constant of RL circuit is L/R
14. The process of converting pulses into spikes is called Tilt
15. Write the relationship between time constant and tilt?Linear wave shaping
UNIT-2 : Non linear wave shaping
1. A comparator is a basic building block in a system used to analyze the ——– distribution of noise generated in active device [ b]
a) Both frequency and phase b) Amplitude c) Phase d) Frequency
2. Zener diode has ———- temperature coefficient [ b]
a) sometimes positive and sometimes negative b) Only negative.
c) Both positive and negative d) Only positive
3. A clamping circuit is also called as ____________. [ c ]
(a) dc restorer (b) dc reinserter (c) both a and b (d) none of the above
4. A clipping circuit consists of ___________. [ c]
(a) Resistor (b) Diode (c) both a and b (d) c and capacitor
section II: fill in the blanks
5. The clamping theorem is given by Af/Ar=Rf/R
6. When the diode is forward biased it acts as closed switch
UNIT-III: SWITCHING CHARACTERISTICS OF DEVICES
1. Common base configurations is little used because [ C]
a) High voltage gain b) High current gain c) It has low input impedance d) High input impedance
2. The Vce (sat) of Si n-p-n transistor at 27 c is [ B ]
a) 0.7 v b) 0.3 v c) 0.8 v d) 0.1 v
3. Turn off time of the transistor is = ——- [A ]
a) toff =tf +ts b) toff =tf +ton c) toff =tfd +ts d) toff =ton +ts
Unit-IV: multivibrators
Section-I: Multiple choice questions
1. Monostable multivibrators generates [ b ]
a) Pulse wave form b) Ramp signal c) Sine wave d) Square wave
2. A sinusoidal waveform can be converted to a square waveform by using _______ [ c ]
(a) Astable multivibrator (b) Bitable multivibrator (c ) Schmitt trigger (d) None of the above
3. A Schmitt trigger is a __________. [ a]
(a) counter (b) Voltage to frequency converter (c) Comparator (d) None of the above
Section-I: Fill in the blanks:
1. A bistable multivibrator is used for 0.5MHz
2. The time constant of a monostable multivibrator is 2.2τ = 2.2RC = 0.35/f2
3. _______________ circuit is used to generate the sequence of pulses which are regularly spaced in time
4. No of quasi stable states of astable is 2
5. The expression of pulse width for monostable multivibrator is (T/2RC) X 100
1. There are four commonly occurring non-sinusoidal waveforms
2. The circuit obstructs the low frequencies while it allows high frequencies to reach output is called High Pass RC Circuit
3. For high pass RC circuit the time constant is given by t=RC
4. With an Integrator the initial conditions can be easily introduced in the circuit
5. The equation obtained by equating denominator polynomial of a transfer function to zero, is called the Characteristic Equation
6. The clippers are also called Slicers or Voltage Limiters
7. The Voltage equivalence of temperature indicates dependence of diode current on temperature
8. The positive series clipper can be obtained by changing the direction of diode innegative clipper circuits
9. As transistor shows Non-Linear behavior it is used for clipping
10. The electronic circuits which are used to generate non-sinusoidal waveforms are called Multi-Vibrators
11. The Binary Multi-Vibrators is used for the performance of many digital operations such as counting and storing
12. The Symmetrical Triggering uses only one trigger input to the input of any one transistor
13. The exponential term in the expression of sweep speed indicates that the charging is Linear
14. The linearity of the sweep voltage will improve if Sweep Speed is constant
15. The interval between pulses must be less than the natural period of the sweep generator i.e, TP<T0
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