Top 150+ Solved Electromagnetic Interference MCQ Questions Answer
Q. An ammeter is a
a. secondary instrument
b. absolute instrument
c. recording instrument
d. integrating instrument
Q. In a portable instrument, the controlling torque is provided by
a. spring
b. gravity
c. eddy currents
d. all of the above
Q. The desirable static characteristics of a measuring system are
a. accuracy and reproducibility
b. accuracy, sensitivity and reproducibility
c. drift and dead zone
d. static error
Q. The ratio of maximum displacement deviation to full scale deviation of theinstrument is called
a. static sensitivity
b. dynamic deviation
c. linearity
d. precision or accuracy
Q. Systematic errors are
a. instrumental errors
b. environmental errors
c. observational errors
d. all of the above
Q. The gravity controlled instrument has crowded scale because current isproportional to
a. balancing weight
b. deflection angle
c. sine of deflection angle
d. none of the above
Q. Instrument transformers are
a. potential transformers
b. current transformers
c. both (a) and (b)
d. power transformers
Q. The damping force acts on the moving system of an indicating instrumentsonly when it is
a. moving
b. stationary
c. near its full scale deflection
d. just staring to move
Q. A moving iron ammeter coil has few turns of thickwire in order to have:
a. high sensitivity
b. effective damping
c. low resistance and large current carrying capacity
d. large scale
Q. Swamping of resistance is used to compensate errordue to:
a. stray magnetic field
b. temperature variations
c. large supply variations
d. none of the above
Q. A 3810/63 P.T. is used with a voltmeter gives reading of 28.11 V , then theactual line voltage is ------ V
a. 0.4648
b. 975
c. 1700
d. 1100
Q. A 1000:5 C.T. is used with an ammeter. If ammeter reading is 1.8 A then theactual line current is --------------A
a. 160
b. 400
c. 0.09
d. 360
Q. While testing cables the galvanometer used should be initially short-circuitedin order to protect it from sudden initial inrush currents as the cable have:
a. a low value of initial resistance
b. a low value of initial capacitance
c. a high value of initial capacitance
d. both (a) and (b)
Q. A megger indicates infinity when test terminals are open-circuited. This isbecause:
a. no current flows through the current coil
b. no current flows through the pressure coil
c. no current flows through the compensating winding
d. current does not flow through current coil and pressure coil