# Past Papers Basic Electronics Instrumentation

## Guess Paper 1: Basic Electronics Instrumentation Fall – 2020 Past Papers

University Name – Confidential

NOTE: Q.1 is compulsory, attempt any four questions from the remaining. All questions carry equal marks. Phones and other Electronic Gadgets are not allowed.

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1 a) The series ohmmeter in given figure is made up of a 1.5V battery, a 100 microamperes meter and a resistance R1 which makes ( R1 + Rm ) = 15 kilo-ohm. Determine the instrument indication when Rx = 0
b) Determine how the resistance scale should be marked at 0.5 Full scale deflections, 0.75 FSD.

b) Discuss the internal circuit of DC voltmeter

Q.2 a) Draw the circuit diagram of a basic two transistor flip flop. Explain the conditions that keep one transistor ON and the other one OFF.
b) Draw the logic diagram for a general ADC.

Q.3 a) Draw the basic block diagram of a digital frequency meter, sketch the system waveforms, and carefully explain its operation.
b) A 20V dc voltage is measured by analog and digital multi-meters. The analog instrument is on its 25 V range, and its specified accuracy is 2% the digital meter has a 3.5 digital display and an accuracy of (0.6+1). Determine the measurement accuracy in each case.

Q.4 Discuss the electronic meters for measurement of very high and very low resistances

Q.5 a) Sketch RL series and parallel equivalent circuits for an inductor.
b) When the given circuit is in resonance. E=100 mV, R = 5 Ohms and XL= Xc= 100 Ohms. Calculate the Q factor.

Q.6 Draw the block diagram for a digital spectrum analyzer. Explain its operation

Q.7 Explain the basic operation of a digital storage oscilloscope, and discuss the relationship between sampling rate and bandwidth.

Q.8 Write note on any TWO of the following:
a) Thermocouple instruments
b) Unregulated DC power supply
c) Low frequency signal generator