Test Papers on Diploma Electronics Engineering

1. In a flux meter, the controlling torque is
(a) produced by weight attached to the moving coil
(b) produced by spring
(c) provided by cross coil mechanism
(d) not provided by all

2. Moving coil galvanometer is made into a dc ammeter by connecting
(a) a low resistance in series with the meter
(b) a high resistance in series with the meter
(c) a pure inductance across the meter
(d) a capacitor in series with the meter

3. The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum, when the operative field of the instrument and stray fields are
(a) perpendicular
(b) parallel
(c) inclined at 60º
(d) none of these

4. A current i = 10(1+sint) amperes is passed through an ideal moving iron type ammeter. Its reading will be
(a) Zero
(b) 10 A
(c) √150 A
(d) √2 A

5. For a given frequency the deflecting torque of an induction ammeter is directly proportional to
(a) current2
(b) current3
(c) √current
(d) current

6. The sensitivity of a Wheatstone bridge depends upon
(a) galvanometer current sensitivity
(b) galvanometer resistance
(c) bridge supply voltage
(d) all of the above

7. The resistance of a shunt for a precision grade ammeter can be best measured by
(a) Wheatstone bridge
(b) Schering bridge
(c) Maxwell bridge
(d) Kelvin double bridge

8. A dc potentiometer is designed to measure up to about 2V with a slide wire of 800mm. A standard cell of emf 1.18V obtains balance at 600mm. A test cell is seen to obtain balance at 680mm. The emf of the test cell is
(a) 1.00V
(b) 1.34V
(c) 1.5V
(d) 1.7V

9. Hay’s bridge is suitable for self inductance measurement of a coil having Q factor
(a) > 10
(b) < 10
(c) > 1
(d) < 1

10. The time base signal in a CRO is
(a) a sinusoidal signal
(b) square wave signal
(c) saw tooth signal
(d) triangular wave signal

11. The lissajous pattern appearing on the screen of a CRT, when two sinusoidal voltages of equal frequencies, which are in phase with each other are applied to the CRO is
(a) a straight line
(b) a circle
(c) an ellipse
(d) a parabola

12. In an ideal Op-Amp the voltage gain for the common mode signal is
(a) Zero
(b) 0.5
(c) 2.0
(d) ∞

13. An Op-Amp has an open loop gain of 105 and an upper cut-off frequency of 10Hz. If this Op-Amp is connected as an amplifier with a closed loop gain of 100, then the new upper cut-off frequency is
(a) 10Hz
(b) 100Hz
(c) 10kHz
(d) 100kHz

14. The voltage comparator can be used in A/D conversion as a
(a) 1-bit quantizer
(b) 2-bit quantizer
(c) 4-bit quantizer
(d) 8-bit quantizer

15. The main advantage of a successive approximation ADC is that
(a) it is independent of its chopper frequency
(b) it has high series mode rejection
(c) it can operate faster than other ADCs
(d) its conversion time can be varied

16. Which of the following terms is not associated with a S/H circuit?
(a) conversion time
(b) acquisition time
(c) aperture time
(d) sample time

17. The number comparators needed in parallel conversion type 8-bit ADC is
(a) 8
(b) 16
(c) 255
(d) 256

18. IEEE488 standard is based on the transmission of
(a) 4 bit
(b) 8 bit
(c) 16 bit
(d) 24 Bit

19. A digital voltmeter has a readout range from 0 to 999 counts. If the full scale reading is 9.999V, the resolution is
(a) 1V
(b) 10mV
(c) 1mV
(d) 0.001mV

20. The household analog energy meter is
(a) indicating instrument
(b) recording instrument
(c) integrating instrument
(d) none of these

21. A moving iron instrument gives correct reading when used at
(a) low frequencies
(b) high frequencies
(c) only one frequency
(d) any frequencies up to certain value

22. the signal to noise ratio in telemetry should be
(a) 5 dB
(b) 10 dB
(c) 25 dB
(d) 60 dB

23. A transducer must have
(a) good dynamic response
(b) good sensitivity
(c) good resolution
(d) all of above

24. Piezo electric effect can be used to measure
(a) Force
(b) Strain
(c) Acceleration
(d) all of above

25. A resistance strain gauge has a resistance of
(a) 100Ω
(b) 25Ω
(c) 10Ω
(d) 1Ω

More Question Set on Electronics Engineering Diploma MCQs from Various Exam

26. The term ‘Poisson’s ratio’ is connected with
(a) strain gauge
(b) LVDT
(c) bourden tube
(d) thermistor

27. Which bridge can be used to measure frequency?
(a) Maxwell
(b) Kelvin
(c) Schering
(d) Wien

28. The instrument used to check insulation of household wiring is
(a) Megger
(b) ohm-meter
(c) multimeter
(d) All of above

29. The current in a circuit is measured using a 150:1 CT. If the ohm-meter reads 0.6A, the circuit current is
(a) 250A
(b) 90A
(c) 156A
(d) 144A

30. To increase the Q factor of a coil, the wire should be
(a) Long
(b) Thin
(c) Thick
(d) long & thin

31. Which of these has a magnetic brake?
(a) thermo couple ammeter
(b) energy meter
(c) dynamometer ammeter
(d) frequency meter

32. A 0 – 200V voltmeter has a sensitivity of 1KΩ/V. The resistance of the voltmeter is
(a) 100KΩ
(b) 200KΩ
(c) 1KΩ
(d) 50KΩ

33. RTD is generally suitable for temperature of about
(a) 50ºC
(b) 200º C
(c) 800ºC
(d) 1500º C

34. If current through the coil of a electromagnet is doubled, then the magnetic field around the coil is
(a) Halved
(b) Doubled
(c) four folded
(d) same

35. The Y plates of a CRO are excited by a voltage 2sin(100t) and X plates are not connected. The display would be
(a) a vertical line
(b) a horizontal line
(c) a sine wave
(d) a slanting line

36. Load cells use
(a) piezo electric effect
(b) capacitor
(c) mutual inductance
(d) strain gauge

37. It is required to measure temperature in the range of 1300º–1520ºC. The most suitable thermo couple is
(a) chromel- constantan
(b) iron-constantan
(c) chromel-alumel
(d) platinum-rhodium

38. Which is the displacement transducer with excellent sensitivity, linearity and resolution?
(a) incremental encoder
(b) absolute encoder
(c) LVDT
(d) strain gauge

39. A digital frequency counter can be converted to DVM by addition of a suitable
(a) VCO
(b) D/A converter
(c) power amplifier
(d) Op-Amp

40. Which one of the following effects is used in measuring power?
(a) Seebeck
(b) Ferranti
(c) Induction
(d) hall

41. Shaft encoder is used to measure
(a) angular position
(b) linear position
(c) linear velocity
(d) angular velocity

42. The input impedance of a CRO is about
(a) Zero
(b) 10Ω
(c) 100Ω
(d) 1MΩ

43. Which of the following is not a piezo-electric material?
(a) Rochell salt
(b) Quartz
(c) lithium sulphate
(d) sodium-bicarbonate

44. A land line tele-metering system is suitable for distance up to about
(a) 1Km only
(b) 10Km only
(c) 100km only
(d) any of the above

45. An electrostatic Voltmeter is suitable for measuring
(a) low voltage at high frequency
(b) high voltage
(c) low voltage at low frequency
(d) all ac and dc voltages

46. If f(t) = -f(- t) and f(t) satisfies Drichlet conditions then f(t) can be expanded in Fourier series having
(a) sine terms alone
(b) cosine terms alone
(c) cosine and constant terms
(d) sine and constant terms

47. The positive peak of an AM wave is 16V and the minimum value is 4V. Assuming single tone modulation, the modulation index is
(a) 0.6
(b) 0.25
(c) 4
(d) 0.36

48. In single tone AM modulation, the transmission efficiency for m=1 is
(a) 33.3%
(b) 50%
(c) 100%
(d) 16.65%

49. Satellite communication uses
(a) 3 to 6 GHz
(b) 3 to 10 MHz
(c) 10 to 50 GHz
(d) 100 to 200 GHz

50. The rate at which information can be carried through a communication channel depends on
(a) carrier frequency
(b) bandwidth
(c) transmission loss
(d) transmitted power