Principles of Electronic Instrumentation Mid - I, September - 2014

1.Sine waves have the unique property that their ______________ is unaffected by linear circuits or systems.
  • Amplitude
  • Phase
  • Shape
  • Power
Answer: C
2.Tuned detectors (tuned over a frequency range) which are capable of selecting and measuring particular harmonics or intermodulation products are called ______________.
  • Wave analyzers
  • Network analyzers
  • Four-arm bridge
  • Radio frequency bridge
Answer: A
3.A quick test for freedom from overload is to double the input amplitude and verify that the output response ____________ without change of shape.
  • Remains same
  • Is attenuated
  • Doubles in amplitude
  • Becomes zero
Answer: C
4.The principal distortion of the square wave is caused by phase shift of ______
  • fundamental frequency alone
  • All harmonics
  • Fundamental frequency and lower harmonics
  • Lower harmonics alone
Answer: C
5.Which is not the problem of DC amplifier?
  • The requirement of a finite input to bring the output to zero
  • A slow variation of the output when the input is constane
  • Unpredictable current in the input leads
  • Maintaining low CMRR
Answer: D
6.Advantage of the peak-responding voltmeter is
  • Susceptibility of the peak-responding meter to errors caused by harmonic distortion
  • Limited sensitivity of the instrument
  • Unsymmetrical input causes different reading
  • Rectifying diode and storage capacitor may be taken out of instrument
Answer: D
7.______________ is an extremely valuable instrument to use for measuring signals in the presence of noise and spurious signals
  • Direct current probes
  • Alternating current probes
  • Sampling voltmeter
  • Synchronous detector
Answer: D
8.Impedance (Z) is
  • Resistance+j*susceptance (R+jB)
  • Resistance+j*reactance (R+jX)
  • Conductance+j*susceptance (G+jB)
  • Conductance+j*reactance (G+jX)
Answer: B
9.Which of the following is not a representation of storage factor Q?
  • 1/D
  • Y/Z
  • X/R
  • B/G
Answer: B
10.Capacitors with dielectrics having dipole moments exhibit
  • Interfacial polarization
  • Dielectric absorption
  • Voltage recovery
  • Molecular polarization
Answer: D
11.Phase detectors are commonly used as null detectors to tell when the two waves have _____ phase shift.
Answer: Exactly 900
12.____________________ time is based upon the earth’s orbital revolution around the sun
Answer: Ephemeris time
13.The mean solar second is _____________ of a mean solar day
Answer: 1/86,400
14._____________ masers produce less high-frequency noise in their outputs.
Answer: Atomic hydrogen
15.The piezoelectric effect in certain crystals, particularly _____ has long been used to stabilize the frequencies of oscillators.
Answer: Quartz
16.A technique called ________ has been incorporated into many DVMs to increase their ability to reduce and eliminate the efforts of common-mode signals.
Answer: Guarding
17.The maximum error with second harmonic distortion occurs when second harmonic is ________ phase with the fundamental.
Answer: 1800
18.The open-circuit transfer inductance between two coupled coils is called as _____________
Answer: Mutual inductance
19.If a voltage is applied to one pair of terminals causes short circuit current to appear at another pair, the ratio of response current to applied voltage is called _____________
Answer: Short circuit transfer admittance
20.The resolution of instruments which use successive-approximation technique is _______ significant bits.
Answer: 3 to 5