Up To Date Electrical Measurements MCQs – Oscilloscopes ( Electrical Measurements ) MCQs
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Electrical Measurements MCQs – Oscilloscopes ( Electrical Measurements ) MCQs
The most occurred mcqs of Oscilloscopes ( ) in past papers. Past papers of Oscilloscopes ( Electrical Measurements ) Mcqs. Past papers of Oscilloscopes ( Electrical Measurements ) Mcqs . Mcqs are the necessary part of any competitive / job related exams. The Mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Oscilloscopes ( Electrical Measurements ) Mcqs. The Important series of Oscilloscopes ( Electrical Measurements ) Mcqs are given below:
TTL Triggering
1. How many, time base generators are provided to a CRO?
a) 2
b) 4
c) 6
d) 8
Answer: a
Explanation: A Cathode Ray Oscilloscope has two time base generators. A time base generator has various sweep modes based on the complexity of the second time base generator.
2. TTL trigger mode is not used for any purpose.
a) True
b) False
Answer: b
Explanation: The TTL trigger mode in a Cathode Ray Oscilloscope is useful in the case of ringing effects. Ringing effects lead to the formation of unwanted oscillations due to switching transients.
3. CRO waveform is disturbed due to _____________
a) Capacitor banks
b) RTL triggering
c) TTL triggering
d) Voltage sources
Answer: c
Explanation: In a Cathode Ray Oscilloscope, the waveform is affected as a result of TTL trigger mode. The lead inductance of the ground along with probe capacitance results in a resonance circuit.
4. Ringing effects can cause false triggering.
a) True
b) False
Answer: a
Explanation: The TTL trigger mode in a Cathode Ray Oscilloscope is useful in the case of ringing effects. Ringing effects produce false triggering even though the trigger points may not be set.
5. How can false triggering be prevented?
a) using RTL logic
b) using TTL logic
c) using DTL logic
d) using flip flops
Answer: b
Explanation: In a Cathode Ray Oscilloscope, TTL trigger circuit is used for setting the correct trigger points. The trigger circuit acts in the same way as the input of a TTL circuit.
6. What is the significance of the TTL trigger mode?
a) initiates interference
b) attenuates the signal
c) prevents interference
d) boosts the signal
Answer: c
Explanation: In a Cathode Ray Oscilloscope, TTL trigger circuit prevents sweep signals that are below the trigger gap from getting triggered falsely.
7. TTL triggering gives a ____________
a) attenuated output
b) magnified output
c) unstable output
d) stable output
Answer: d
Explanation: TTL triggering circuit in a Cathode Ray Oscilloscope gives rise to a stable display. There is no necessity to check the TTL levels on the screen. The logic levels are also checked to be correct.
8. Switched sweep mode is also known as ____________
a) dual sweep mode
b) single sweep mode
c) quadruple sweep mode
d) triple sweep mode
Answer: a
Explanation: A switches sweep mode is used for displaying two independent variable sweep modes in an alternative fashion. Initially, waveform is displayed with a slow sweep rate and then with a fast sweep rate.
Dual Trace Oscilloscope
1. Why a dual slope oscilloscope is needed?
a) to compare more than two voltages
b) to measure the voltage
c) to measure the current
d) to measure the time
Answer: a
Explanation: A dual trace oscilloscope is required for comparison for two or more voltages in the analysis and study of electronic circuits and systems.
2. What is the problem with using more than one oscilloscopes?
a) measuring the signal’s parameters
b) triggering
c) supply voltage
d) errors in reading
Answer: b
Explanation: When one more than one oscilloscope is used, the trigger sweeps of each can’t be synchronized simultaneously. As a result dual trace oscilloscopes are used in order to save the cost.
3. Independent traces can be obtained using ____________
a) 4 methods
b) 6 methods
c) 2 methods
d) 8 methods
Answer: c
Explanation: In order to generate two independent traces in a oscilloscope, two methods are used. One method is known as the sweep method whereas the other is known as the chop method.
4. Two methods are used to generate independent traces.
a) True
b) False
Answer: a
Explanation: In a Cathode Ray Oscilloscope, two methods are used to generate two independent traces. The first method is an alternate sweep method while the second is the chop method.
5. How many vertical inputs exist in a dual trace oscilloscope?
a) 8
b) 6
c) 4
d) 2
Answer: d
Explanation: In a Dual Trace Oscilloscope, two vertical inputs exist. The two channels are known as A and B. A separate preamplifier and an attenuator stage exist for each channel. The amplitude of each input can be controlled separately.
6. After pre-amplification the signals are fed into ____________
a) an electronic switch
b) a signal generator
c) a rectifier
d) a regulator
Answer: a
Explanation: In a Dual Trace Oscilloscope, after the pre amplification process is done, the signals are fed into an electronic switch. The switch passes one channel at a time through the delay line.
7. X-Y mode means ____________
a) 2 modes
b) vertical and horizontal
c) x axis and y axis
d) ground and full line supply
Answer: b
Explanation: In a Dual Trace Oscilloscope, X-Y mode means the oscilloscope operates from the first channel A as a vertical signal and from the second channel B as a horizontal signal.
8. Electronic switch is controlled by ____________
a) D flip-flop
b) SR flip-flop
c) T flip-flop
d) JK flip-flop
Answer: c
Explanation: In the Dual Trace Oscilloscope, an electronic switch is controlled by making use of a T flip-flop which is also known as a toggle flip-flop. Switching occurs during the beginning of a new sweep.
9. Which technique of a Dual Trace Oscilloscope maintains the phase between the signals?
a) Analog mode
b) Mixed mode
c) Chop mode
d) Alternate mode
Answer: d
Explanation: In a Dual Trace Oscilloscope, the alternate mode of operation enables to maintain the correct phase relationship between the signals from the channels A and B.
Electronic Switch & Dual Beam Oscilloscope
1. Electronic switch is used in a dual trace oscilloscope.
a) True
b) False
Answer: a
Explanation: By using a single CRT gun, two signals can be displayed on the screen simultaneously by means of an electronic switch.
2. Signals are applied to ___________
a) input
b) gain control stage
c) output
d) capacitor
Answer: b
Explanation: In a dual trace oscilloscope, the signals are applied to the gain control as well as the gate control stage.
3. What adjusts the amplitudes of the signals A and B?
a) L1 and L2
b) C1 and C2
c) R1 and R2
d) Oscillator
Answer: c
Explanation: In a dual trace oscilloscope, the resistances R1 and R2 are used for adjusting the magnitudes of the amplitudes of the signals A and B of the two channels A and B.
4. What is the role of a square wave generator?
a) generates square waves
b) generates triangular waves
c) generates saw-tooth signals
d) generates alternate inputs
Answer: d
Explanation: A square wave generator in a dual trace oscilloscope provides alternate biasing signals to the switches Q3 and Q4.
5. How many switches work at a time?
a) 1
b) 3
c) 2
d) 5
Answer: a
Explanation: In a dual trace oscilloscope, the square wave generator provides alternate bias signals to the switches Q3 and Q4. When Q3 is conducting, Q4 remains off while Q3 is off, Q4 conducts.
6. Square wave generator doesn’t reproduce the signals on the screen.
a) True
b) False
Answer: b
Explanation: In a dual trace oscilloscope, the square wave generator reproduces two signals on the screen. When the switching frequency of the square wave generator is higher than that of the individual signals, the bits of each signal are provided alternately to the vertical inputs.
7. A multitrace oscilloscope makes use of __________
a) three traces
b) two traces
c) many traces
d) one trace
Answer: c
Explanation: In a multitrace oscilloscope, a signle electron beam is used. It makes use of several traces by switching the Y deflection plates from one input signal to the other.
8. A dual beam oscilloscope has __________
a) 2 beams
b) 4 beams
c) 6 beams
d) 8 beams
Answer: a
Explanation: In a dual beam oscilloscope, the beams are deflected horizontally by means of a common set of plates. Each electron beam has its own set of vertical deflection plates.
9. Two voltages can be studied simultaneously by making use of __________
a) single electron gun
b) two electron guns
c) four electron guns
d) six electron guns
Answer: b
Explanation: On the Cathode Ray Oscilloscope, two voltages can be studied simultaneously by means of two electron guns generating two separate beams through a special cathode ray tube.
10. A dual beam oscilloscope has __________
a) 8 vertical deflection plates
b) 6 vertical deflection plates
c) 2 vertical deflection plates
d) 4 vertical deflection plates
Answer: c
Explanation: In a dual beam oscilloscope, there are two vertical deflection plates and two separate channels. Each channel consists of a preamplifier and an attenuator stage.
11. Sweep generator is triggered by __________
a) oscillator
b) flip-flop
c) transformer
d) channel A or B
Answer: d
Explanation: In a dual beam oscilloscope, the sweep generator is triggered internally by means of either the channel A signal or the channel B signal.
12. A sweep generator can be triggered by an external switch as well.
a) True
b) False
Answer: a
Explanation: In a dual beam oscilloscope, the sweep generator can be triggered by means of an external switch or a line frequency signal. This is done through means of a trigger selector switch.
13. A dual beam oscilloscope has same sweep rates for different channels.
a) True
b) False
Answer: b
Explanation: In a dual beam oscilloscope, the sweep rates are different for different channels. As a result the size and weight of the oscilloscope is increased. A dual beam oscilloscope has a separate time-base for different channels.
14. In a multi-beam oscilloscope __________
a) single beam is produced
b) three beams are produced
c) many beams are produced
d) two beams are produced
Answer: c
Explanation: In a multi-beam oscilloscope, several beams are produced from a single tube. Each system is made up of a separate set of vertical deflection plates and a common time base system.
Digital Storage Oscilloscope
1. What is the main advantage of using a digital storage oscilloscope?
a) uses digital storage
b) uses analog storage
c) uses mixed mode storage
d) uses disc storage
Answer: a
Explanation: The disadvantage of a analog storage oscilloscope is overcome in a digital storage oscilloscope. The unreliable storage method in a analog storage oscilloscope is overcome in a digital storage oscilloscope. The digital storage oscilloscope makes use of digital storage for the memory.
2. The memory of a digital storage oscilloscope is limited.
a) True
b) False
Answer: b
Explanation: In a digital storage oscilloscope, the memory can store data as long as required without degradation. It makes use of complex signal processing techniques through high speed digital signal processing.’
3. The waveform is stored in _________
a) compressed form
b) analog form
c) digital form
d) mixed form
Answer: c
Explanation: The waveform to be studied is stored in digital form in the digital storage oscilloscope. It is digitized and stored in a digital memory.
4. Which oscilloscope is used in a digital storage oscilloscope?
a) multi trace
b) dual trace
c) modern
d) conventional
Answer: d
Explanation: A digital storage oscilloscope makes use of a conventional cathode ray tube. As a result, the cost is reduced.
5. Power requirement is _________
a) low
b) high
c) medium
d) zero
Answer: a
Explanation: In a digital storage oscilloscope, the power required by the memory is less. It can be supplied through the means of a small battery.
6. The stored image can be displayed _________
a) for a limited time
b) for infinite time
c) for zero time
d) for an intermediate time
Answer: b
Explanation: In a digital storage oscilloscope, the stored image can be displayed for a long time as long as the power supply to the digital memory is kept intact without any kind of disruption.
7. The analog signal is digitized using _________
a) D/A converter
b) Oscillator
c) A/D converter
d) Rectifier
Answer: c
Explanation: In a digital storage oscilloscope, the analog signal is digitized by making use of an analog to digital converter. After digitizing the waveform is loaded into a computer and can be analyzed.
8. How is the data displayed?
a) through a screen
b) through a computer
c) through an FPGA
d) through a microprocessor
Answer: d
Explanation: In a digital storage oscilloscope, the data is displayed by passing it through a microprocessor which processes the data and displays the waveform onto a screen.
9. A digital storage oscilloscope has _________
a) 3 modes
b) 2 modes
c) 4 modes
d) 5 modes
Answer: a
Explanation: In a digital storage oscilloscope, there are three modes of operation. They are as follows:
• Store
• Roll
• Hold or Save.
CRO Measurements
1. By making use of a CRO _________
a) many characteristics of a signal can be measured
b) only a few characteristics of a signal can be measured
c) no characteristics of a signal can be measured
d) signal can only be displayed
Answer: a
Explanation: Through the means of a Cathode Ray Oscilloscope, most of the characteristics of an input signal can be measured. Properties of a signal can be studied as well.
2. How is the waveform adjusted?
a) by adjusting the voltage
b) through shift controls
c) by reducing the current
d) by means of a galvanometer
Answer: b
Explanation: In a Cathode Ray Oscilloscope, the waveform can be adjusted by means of shift controls. As a result, the measurement of divisions corresponding to the amplitude becomes easy.
3. How is error in measurement reduced?
a) using r.m.s value
b) using absolute value
c) using peak to peak value
d) using a voltmeter
Answer: c
Explanation: In a Cathode Ray Oscilloscope, the error in measurement is reduced by making use of the peak to peak value.
4. Peak to peak voltage is given by ________
a) Vp-p = number of units × \((\frac{1}{division})\)
b) Vp-p = \((\frac{volts}{division})\)
c) Vp-p = number of units × volts
d) Vp-p = number of units × \((\frac{volts}{division})\)
Answer: d
Explanation: In a Cathode Ray Oscilloscope, the peak to peak voltage is given by the relation,
Vp-p = number of units × \((\frac{volts}{division})\)
where, Vp-p is the peak to peak voltage.
5. The amplitude of voltage is given by which of the following relation?
a) Vm = \(\frac{V_{p-p}}{2}\)
b) Vm = \(\frac{V_{p-p}}{4}\)
c) Vm = 2 × Vp-p
d) Vm = 4 × Vp-p
Answer: a
Explanation: In a Cathode Ray Oscilloscope, the amplitude of voltage is given by the relation,
Vm = \(\frac{V_{p-p}}{2}\)
where, Vp-p is the peak to peak voltage
Vm is the amplitude.
6. The R.M.S voltage is given by which of the following relation?
a) Vrms = \(\frac{V_m}{2}\)
b) Vrms = \(\frac{V_m}{\sqrt{2}}\)
c) Vrms = \(\frac{V_m}{8}\)
d) Vrms = \(\frac{V_m}{\sqrt{8}}\)
Answer: b
Explanation: The r.m.s value of voltage is given by the relation,
Vrms = \(\frac{V_m}{\sqrt{2}}\)
where, Vrms is the r.m.s value of voltage
Vm is the amplitude of the voltage.
7. CRO is voltage measuring device.
a) True
b) False
Answer: a
Explanation: Generally, a CRO is a voltage measuring device. Current is measured by passing current through a known value of resistance. Voltage across the resistance is displayed on the screen of the CRO.
8. Period of a waveform is obtained by which of the following relation?
a) T = number of divisions occupied by 1 cycle×(time)
b) T = number of divisions occupied by 1 cycle×(1⁄division)
c) T = number of divisions occupied by 1 cycle×(time⁄division)
d) T = number of divisions occupied by 1 cycle
Answer: c
Explanation: The time period of a waveform is obtained by using the relation,
T=number of divisions occupied by 1 cycle×(time⁄division).
9. How is frequency related to time period?
a) square proportional
b) not related
c) directly proportional
d) inversely proportional
Answer: c
Explanation: Frequency is inversely proportional to the time period of any given signal.
f = 1⁄t
where, f is the frequency
T is the time period.
Acquisition Methods
1. How many types of acquisition methods are there in a digital storage oscilloscope?
a) 3
b) 6
c) 2
d) 4
Answer: a
Explanation: In a digital storage oscilloscope, there are three methods in which a digital signal can be captured and stored. They are as follows:
i) Real time sampling
ii) Random repetitive sampling
iii) Sequential repetitive sampling.
2. An oscilloscope with 20 to 50 GHz needs a slow speed.
a) True
b) False
Answer: b
Explanation: For an oscilloscope with a bandwidth of 20 to 50 GHz, a high speed network setting is required. This is achieved through the means of the sequential repetitive sampling.
3. In which method of acquisition, pretrigger event is lost?
a) Real time sampling
b) Random repetitive sampling
c) Sequential repetitive sampling
d) Analog Sampling
Answer: c
Explanation: In Sequential repetitive sampling, pretrigger information cannot be captured. And the pretrigger view is lost. It can be used only in microwave digital oscilloscope as a result.
4. In Sequential repetitive sampling how many samples are captured?
a) ten
b) five
c) two
d) one
Answer: d
Explanation: In Sequential repetitive sampling, one sample is captured at a controlled time delay of tds. After each point is captured, the delay is increased by a small amount tse/sub>.
5. In Real time sampling, bandwidth is limited.
a) True
b) False
Answer: a
Explanation: In Real time sampling, the bandwidth is only ¼ of the actual value. As a result to increase the bandwidth, fast sample rate digitizers and memory are required which are very expensive.
6. Nyquist criteria states that ______________
a) Fs = fmax/2
b) Fs ≥ 2fmax
c) Fs = fmax
d) Fs = 2
Answer: b
Explanation: Nyquist criteria states that the sampling rate is twice the maximum frequency. It is given by the relation.
Fs≥2fmax
where, Fs is the sampling rate
fmax is the maximum frequency.
7. What plays an important role in Real time sampling?
a) small memory and fast sampling
b) large memory and slow sampling
c) large memory and fast sampling
d) small memory and slow sampling
Answer: c
Explanation: In Real time sampling, a higher sampling rate is required to capture long time interval signal capturing. Large memory and a fast sampling rate are the characteristic feature of real time sampling.
8. A single trigger event can capture how many samples in Real time sampling?
a) 1
b) nm/2
c) 2nm
d) nm
Answer: d
Explanation: In Real time sampling, a trigger event can be used to capture as much as nm samples. The waveform is then displayed on a digital storage oscilloscope.
9. In Real time sampling what is the 3 dB bandwidth?
a) fs/4
b) fs/8
c) 2fs
d) fs
Answer: a
Explanation: In Real time sampling, the 3 dB bandwidth is set to fs/4 with an overshoot of 5%. Here fs is the sampling frequency.
Applications of CRO
1. CRO is used for measurement of __________
a) AC as well as DC current
b) AC current only
c) DC current only
d) AC power only
Answer: a
Explanation: A Cathode Ray Oscilloscope is used for the measurement of AC as well as DC current. It is used for the calculation peak to peak voltage, r.m.s value, duty cycle, etc.
2. CRO is used in a radar for __________
a) studying the pattern of flights
b) visualizing a target
c) measuring voltage
d) determining the distance between source and destination
Answer: b
Explanation: A Cathode Ray Oscilloscope is used in a radar for visualizing a target such as an aeroplane, ship, etc.
3. In radio applications, CRO is used for measuring __________
a) audio frequency range
b) a narrow range of frequencies
c) a wide range of frequencies
d) radio frequency range
Answer: c
Explanation: By making use of a Cathode Ray Oscilloscope, a wide range of frequencies can be measured. The radio frequency, audio frequency and intermediate frequency signals can be measured by making use of a CRO.
4. In medical applications CRO can be used for __________
a) measuring the heart beats
b) monitoring the brain
c) improving the nervous system functioning
d) displaying cardiograms
Answer: d
Explanation: A Cathode Ray Oscilloscope, can be used in medical applications for displaying cardiograms. Cardiograms are used for diagnosing the condition of heart of a patient. Electromyograms are used for studying the condition of a patient’s muscle.
5. CRO is used for many purposes in the industry.
a) True
b) False
Answer: a
Explanation: A Cathode Ray Oscilloscope, is used for observing B-H curves, P-V diagrams, etc. A CRO is also used in various transducers for the measurement of strain, pressure and temperature.
6. A CRO can’t be used in transmission lines.
a) True
b) False
Answer: b
Explanation: A Cathode Ray Oscilloscope, is used in transmission lines for the measurement of modulation characteristics. It is also used for detecting the standing waves in a transmission line.
7. Curve tracers use CRO in __________
a) diodes
b) passive devices
c) active devices
d) op amps
Answer: c
Explanation: Curve tracers in a Cathode Ray Oscilloscope are used for testing active devices such as vacuum tubes, transistors and integrated circuits.
8. A CRO is used in check __________
a) op amps
b) resistors
c) voltage
d) capacitance, inductance and diodes
Answer: d
Explanation: A Cathode Ray Oscilloscope is used for checking diodes. It is also used in the measurement of inductances and capacitances. A CRO can also be used for detecting the faults in a circuit.
9. A CRO is used in labs for __________
a) frequency measurement
b) voltage measurement
c) current measurement
d) resistance measurement
Answer: a
Explanation: A Cathode Ray Oscilloscope is used in the laboratory for the measurement of frequency, phase and period of a signal. Periodic as well as non-periodic relationships of signals can also be studied.
Advanced Problems on CRT and CRO
1. A recorder is a device ________
a) An indicating instrument which displays a time-varying signal
b) Whose function is to record the value of the quantity as it is being measured
c) Which records electrical and non-electrical quantities or relates two signals to each other as a function of time
d) Which records the value of the quantity measured as well as the electrical and non-electrical quantities as a function of time
Answer: d
Explanation: A recorder is a device which record the value of quantity as it is being measured. It records electrical and non-electrical quantities or relates two signals to each other as a function of time.
2. In a dual slop integrating type digital voltmeter, the firs integrating is carried out for 10 periods of the supply frequency of 50 Hz. If the reference voltage used is 2 V, the total conversion time for an input of 1 V is?
a) 0.01 s
b) 0.05 s
c) 0.1 s
d) 1 s
Answer: c
Explanation: In a dual slope integrating digital voltmeter,
\((\frac{t_1}{t_2})\) Vin = Vref
Where, t1 = first integration time = 10 × \(\frac{1}{50}\) = 0.25
But Vin = 1 V and Vref = 2 V
∴ t2 = \(\frac{V_in t_1}{V_{ref}}\) = 0.1 s.
3. The source of emission of electrons in a circuit is ______________
a) p-n junction diode
b) a barium and strontium oxide coated cathode
c) accelerating anode
d) post-accelerating anode
Answer: d
Explanation: The source of focused and the accelerated electron beam is the electron gun. The electron gun which emits electrons forms them into a beam consisting of a heater, a cathode, a grid, a pre-accelerating anode, a focusing anode and an accelerating anode.
4. A CRO can display _________
a) AC signals
b) DC signals
c) Both AC and DC signals
d) Time-invariant signals
Answer: c
Explanation: A Cathode Ray Oscilloscope cannot measure or display Time invariant signals. However, it can measure both AC and DC signals.
5. X and Y plates of a CRO are connected to unequal voltages of equal frequency with phase shift of 90°. The Lissajous figure on the screen will be?
a) Circle
b) Straight line
c) Ellipse
d) Figure of eight
Answer: c
Explanation: The pattern observed on the CRT, when two sinusoidal signals are applied to the X-X and Y-Y plates of the CRT are known as Lissajous pattern.
sin φ = \(\frac{y_1}{y_2} = \frac{X_1}{X_2}\)
Here, the voltages are unequal and frequencies are equal with a phase shift of 90°. Therefore the Lissajous figure on the screen will be an ellipse.
6. To the Y input of a CRO, we feed a signal defined by 10sin100t, to the X-input, we feed signal 10cos100t. The gain for both X channel and Y channel is the same, the screen will show?
a) Sinusoidal signal
b) A straight line
c) An ellipse
d) A circle
Answer: d
Explanation: The pattern observed on the CRT, when two sinusoidal signals are applied to the X-X and Y-Y plates of the CRT are known as Lissajous pattern.
sin φ = \(\frac{y_1}{y_2} = \frac{X_1}{X_2}\)
∴ Screen will show a circle.
7. A CRO uses _________
a) Electromagnetic focusing
b) Electrostatic focusing
c) Both Electrostatic and Electromagnetic focusing
d) No focusing technique
Answer: b
Explanation: A Cathode Ray Oscilloscope always using the focusing technique for its operation. Electromagnetic focusing is used by the Cathode Ray Tube. However, the Cathode Ray Oscilloscope employs Electrostatic focusing.
8. A CRO probe has an impedance of 500 kΩ in parallel with a capacitance of 10 pF. The probe is used to measure the voltage between P and Q as shown in the figure. The measured voltage will be?
a) 3.53 V
b) 3.47 V
c) 5.54 V
d) 7.00 V
Answer: b
Explanation: XC = \(\frac{1}{jCω} = \frac{-j}{2 × 3.14 × 100 × 10^3 × 10 × 10^{-12}}\)
Applying KCL at node,
\(\frac{V_a-10}{100} + \frac{V_a}{100} + \frac{V_a}{500} + \frac{V_a}{-j159}\)
∴ Va = 4.37∠-15.95°.
9. The two inputs of a CRO are fed with two stationary periodic signals. The figure changes from ellipse to circle and back to ellipse with its major axis changing orientation slowly and repeatedly. The following inference can be made from this.
a) The signals are not sinusoidal in nature
b) The amplitudes of the signals are very close but not equal
c) The signals are sinusoidal with their frequencies very close but not equal
d) There is a constant but small phase difference between the signals
Answer: d
Explanation: X = A sinωt
Y = A sin (ωt-∅t)
Phase difference = ∅t
For ellipse, A1 ≠ A2
For circle, A1 = A2
Hence, there is a constant but small difference between the signals.
10. An oscilloscope indicates ___________
a) The peak to peak value of the voltage
b) DC value of the voltage
c) Rms value
d) Average value
Answer: a
Explanation: The oscilloscope can measure not only the DC value but also the AC value. The RMS value cannot be measured by the oscilloscope. Similarly, the average value is also not measured. Therefore the peak to peak value of the voltage is measured.