Instrumentation Mid - I, September - 2014

1.Thermistors are _______________ sensitive resistors
  • Mechanically
  • Kinematically
  • Thermally
  • Geometrically
Answer: C
2.The two basic requirements of transducers
  • Non linearity, high stability
  • Linearity, high stability
  • Linearity, low stability
  • Non linearity, low stability
Answer: B
3.Single voltage to be observed
  • Is applied to X-plates of CRT
  • Is applied to Y-plates of CRT
  • Is applied to control grid of CRT
  • Provides intensity control
Answer: C
4.Electron emission from the cathode in the CRT in a cathode id due to
  • Field emission
  • Secondry electron emission
  • Thermionic emission
  • Radiation
Answer: B
5.Difference between measured value and true value is called
  • Relative error
  • Absolute error
  • Gross error
  • Probable errors
Answer: B
6.Systamatic errors are
  • Instrumental errors
  • Environmental errors
  • Random errors
  • A & B
Answer: D
7._____________ are obtained at sampling instants because they are obtained by time sampling of continuous time signals
  • Non-linear systems
  • Stable systems
  • Discrete systems
  • None of the above
Answer: C
8.A device or a set of rules defining the functional relation between input & output is known as
  • Signal
  • System
  • Transducer
  • All of the above
Answer: B
9.The rate at which current carries flow is measured in
  • Coulombs
  • Amperes
  • Watt-hour
  • Watts
Answer: B
10.A dynamometer type wattmeter responds to
  • Average value of active power
  • Average value of reactive power
  • Peak value of active power
  • Peak value of reactive power
Answer: A
11.The input resistance of a CRO is of the order of _________________________.
Answer: Mega ohms
12.Resistance thermometer elements made from _____________ compounds are called thermistors.
Answer: Semiconductor
13.The resultant path for an electron entering the magnetic field at an angle is a __________.
Answer: Helix
14.During measurement of phase angle between two sine wave signals, if figure on CRO screen is a circle, the phase difference between signals is ______________.
Answer: 1800
15._____________ is an instrument for indicating differences of phases and frequencies of two circuits.
Answer: Synchoscope
16.Potentiometer is basically a _______________________instrument.
Answer: Null type
17.Examples of periodic signals are _________________ signals.
Answer: Sine, cosine
18.Signals which can be uniquely described by a mathematical expression, table, graph or well defined rule are known as ______________________________.
Answer: Deterministic signals
19.A transfer instrument employed in the standardization of polar type AC potentiometer is a ____________________.
Answer: Dynamometer
20.A voltmeter should have high ______________________ resistance.
Answer: Internal