Name :. Roll No. :... Invigilator s Signature :.. CS/B.TECH (EIE)/SEM-6/EI-603/ ELECTRONIC INSTRUMENTATION & MEASUREMENT

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1 Name :. Roll No. :..... Invigilator s Signature :.. CS/B.TECH (EIE)/SEM-6/EI-603/ ELECTRONIC INSTRUMENTATION & MEASUREMENT Time Allotted : 3 Hours Full Marks : 70 The figures in the margin indicate full ma ks Candidates are required to give their answers in their own words as far as practicable. GROUP A ( Multiple Choice T pe Questions ) 1. Choose the correct alternatives or any ten of the following : 10 1 = 10 i) In modern electronic meters, FET or MOSFET is preferred over BJT as : a) I offers high loading effect. b) Its input impedance is high and does not change with range switch. c) Its input impedance is low d) It is cheaper [ Turn over

2 ii) A digital voltmeter has a read-out range from 0 to When full scale reading is 9.999V, the resolution of the full scale reading is a) b) 1000 c) 3 digit d) 1 mv. iii) In measurements made using a Q-meter, high impedance elements should preferably be connected in a) Star b) De ta c) Series d) Parallel. iv) The purpose of the synchronizing control in CRO is to a) Focus the spot on the screen b) Lock the display of signal. c) Adjust the amplitude of display d) Cont ol the intensity of spot. v) In a digital oscilloscope, the A/D converters are usually a) Ramp type b) Integrating type c) Flash type d) Successive approximation type

3 vi) An ac voltmeter is used to measure a) Average value b) RMS value c) Peak value d) Peak to peak value. vii) The commonly used PLL chip a) NE 500 b) LM 522 c) NE 565 d) NE 465. viii) Spectrum analyzer is a combination of a) Narrow band sup rheterodyne receiver and CRO b) Signal generator and CRO c) Oscillator and wave analyzer. ix) d) VTVM and CRO. In a phase locked loop a) Capture range is smaller than lock in range b) Lock range is smaller than the capture range c) Capture range is equal to lock range d) None of these [ Turn over

4 x) Chopper stabilized de amplifier is used in voltmeters to measure input voltages in the a) kilovolt (KV) range. b) volt(v) range c) milivolt (mv) range. d) microvolt (μv) and nanovolt (nv) range xi) What type of noise is found in a semiconductor device a) Shot noise b) Thermal noise c) Johnson noise d) None of these. xii) Bolometer is used to measure a) Power b) Frequency c) Temperature d) Current. GROUP B ( Short Answer Type Questions ) Answer any three of the following. 3 5 = Explain the oprating principle of swept superheterodyne spectrum analyzer. 3. Briefly explain the working principle of Dual-trace oscilloscope of an CRO?

5 4. With the help of a functional block diagram, explain the working principle of a voltage to frequency converter a) What is the operating principle of LCD? b) What are the advantages of LCD over LED-display? a) With a suitable block diagram explain the peration of voltage controlled oscillator (VCO). b) Explain capture range and Lock-in range in PLL GROUP ( Long Answer Type Questions ) Answer any three of the following = a) Explain with a circuit diagram to show how current can be measured using an electronic voltmeter. b) How is the 4-wire sensing technique superior to the 2- w re s nsing technique? c) Explain the operation of a dual slope integrating type C digital voltmeter. How does the range changing circuit work for a DVM? a) Define the Q-factor of a coil. Explain with a circuit diagram, the construction and principle of operation of a basic Q-meter [ Turn over

6 b) To find the self capacitance of a coil by Q-meter, the resonance was obtained with i) tuning capacitor of 1530pF at 1 MHz ii) tuning capacitor of 162pF at 3 MHz c) What are the errors present in Q-meter? a) What do you mean by DVM b) How many types of DVM. Explain bri fly any one of them with proper sketch. c) With the help of a block diagram, explain the working principle of a true RMS meter d) What is noise? a) What is the use of Lissajous pattern during phase measurement in CRO? b) What are he different probes for CRO? c) What is astigmatism? d) Derive the expression of thermal noise. e) Draw the circuit for a FET input voltmeter using dual emitter follower and an input attenuator

7 11. Write short notes on any three of the following : 3 5 = 15 a) Virtual Instrumentation b) Programmable gain Amplifier c) Current Mirror d) Charge Amplifier e) Distortion meter f) Johnson Noise [ Turn over

SHRI ANGALAMMAN COLLEGE OF ENGINEERING & TECHNOLOGY (An ISO 9001:2008 Certified Institution) SIRUGANOOR,TRICHY

SHRI ANGALAMMAN COLLEGE OF ENGINEERING & TECHNOLOGY (An ISO 9001:2008 Certified Institution) SIRUGANOOR,TRICHY-621105. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING EI 1306-MEASUREMENT AND INSTRUMENTATION