Saturday, February 23, 2013

Instrumentation MCQ Objectives

1. A thermo-couple instrument can be used for the measurement of:
a) Direct current only
b) Alternating current only
c) Both direct current and alternating current
d) dc/ac voltage only


2. Electrostatic type instruments are mainly used for measurement of:
a) Heavy currents
b) Low currents
c) Low voltages
d) High voltages


3. The instrument which is cheapest for dc measurement is:
a) Moving iron
b) PMMC
c) Hot-wire
d) Electro-dynamo 


4. Measurement range of a voltmeter can be extended by using:
a) High current resistance
b) High series resistance
c) Low shunt resistance
d) Low series resistance


5. Which of the following voltmeter have least power consumption:
a) Moving iron
b) Hot-wire
c) Electrostatic
d) Induction type


6. Which of the following instruments have least torque/weight ratio:
a) Dynamometer type
b) PMMC
c) Attraction type moving iron
d) Repulsion type moving iron


7. The instrument having its deflection depends upon average value is:
a) Moving iron
b) Hot wire
c) Rectifier type
d) Induction type


8. Which of the following instruments can be used for full scale deflection of 300o:
a) PMMC
b) Induction type
c) Hot wire
d) Electrostatic


9.While testing cables the galvanometer used should be initially short-circuited in 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)


10. A Ohmmeter is basically:
a) A ammeter
b) A voltmeter
c) A multimeter
d) None of the above


11. A megger indicates infinity when test terminals are open-circuited. This is because:
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


12. Potentiometer is an __ instrument:
a) Indicating
b) Comparison
c) Calibrating
d) Recording


13. Which of the following bridge is frequency sensitive:
a) Wheatstone bridge
b) Maxwell bridge
c) Anderson bridge
d) Wien bridge


14. Tesla coil is a ___ transformer:
a) Coreless
b) Cascaded
c) Low impedance
d) High frequency resonant


15. Direct current is preferred over alternating current for testing of ac transmission lines and cables because:
a) Heavy charging currents will be drawn and so a large sized transformer is required if tested with ac
b) Transmission lines and cables should not be tested with dc
c) The transformers required for testing cannot be used for long distances
d) All the above