Free Measurement and Instrumentation MCQs with Answers

• A. should be mounted in vertical position
• B. should be mounted in horizontal position
• C. either A. or B.
• D. neither A. nor B.

Explanation: Switchboard instruments are mounted vertically so their calibrated movement operates in the intended position and gravity does not…

• A. very light
• B. very heavy
• C. either A. or B.
• D. neither A. nor B.

Explanation: A very light pointer has low inertia, so it responds quickly and does not significantly disturb the moving system.

• A. Mercury motor meters
• B. Commutator motor meters
• C. Induction meters
• D. None of the above

Explanation: Induction meters depend on alternating flux and the resulting eddy currents, so they cannot operate on steady DC.

• A. spring
• B. gravity
• C. eddy currents
• D. all of the above

Explanation: Portable instruments generally use spring control because the spring provides a nearly uniform controlling torque regardless of the…

• A. fluid friction
• B. spring
• C. eddy currents
• D. all of the above

Explanation: Eddy-current damping is widely used because it provides effective damping without physical contact or added friction at the moving system.

• A. conducting and magnetic material
• B. non-conducting and magnetic material
• C. conducting and non-magnetic material
• D. none of the above

Explanation: The disc must conduct electricity so that eddy currents can be induced, but it should be non-magnetic so that damping does not depend on…

• A. by pass the current
• B. increase the sensitivity of the ammeter
• C. increase the resistance of ammeter
• D. none of the above

Explanation: An ammeter shunt is a low-resistance parallel path that bypasses most of the current around the meter movement.

• A. measurement of resistance
• B. measurement of current
• C. calibration of ammeter
• D. calibration of voltmeter
• E. all of the above

Explanation: A potentiometer compares potential differences without drawing current from the source being measured, allowing resistance and current…

• A. D.C. ammeter hour meter
• B. D.C. ammeter
• C. D.C. energy meter
• D. none of the above

Explanation: A DC ampere-hour meter uses the chemical effect of current, with the deposited chemical quantity corresponding to the total charge passed.

• A. potential transformers
• B. current transformers
• C. power transformers
• D. either of the above
• E. none of the above

Explanation: A current transformer reduces a large line current to a safe, proportional value for the wattmeter current coil.

• A. Tangent galvanometer
• B. Meggar
• C. Current transformer
• D. None of the above

Explanation: A Megger, or insulation-resistance tester, measures very high resistance between conductors and between a conductor and earth.

• A. by using a low resistance shunt
• B. by using a high series resistance
• C. by eliminating the control springs
• D. by making control springs of large moment of inertia

Explanation: A PMMC instrument becomes a flux meter when its control springs are removed, so the deflection depends on the total change in flux linkage…

• A. mercury motor meters
• B. commutator motor meters
• C. induction type single phase energy meters
• D. all of the above

Explanation: The induction-type single-phase energy meter is the familiar electromechanical meter used in ordinary domestic and many industrial AC…

• A. 10 A
• B. 30 A
• C. 60 A
• D. 100 A

Explanation: Induction energy meters are commonly designed for direct connection to loads of up to about 100 A; larger currents are handled through…

• A. Absolute
• B. Indicating
• C. Recording
• D. Integrating

Explanation: Integrating instruments accumulate a quantity over time, such as ampere-hours or watt-hours.

• A. absolute
• B. indicating
• C. recording
• D. integrating
• E. none of the above

Explanation: Absolute instruments determine a quantity from the instrument’s physical constants and measured dimensions, so they are mainly used as…

• A. Ammeters
• B. Voltmeters
• C. Wattmeters
• D. Ampere-hour and watt-hour meters

Explanation: Ampere-hour and watt-hour meters integrate current or power over time, giving total charge or energy delivered.

• A. Should be non-magnetic
• B. Most be of low temperature co-efficient
• C. Should have low specific resistance
• D. Should not be subjected to fatigue
• E. All of the above

Explanation: Control springs should be non-magnetic, have a low temperature coefficient, and resist fatigue so their controlling torque remains stable.

• A. ammeter
• B. voltmeter
• C. flux-meter
• D. ballistic galvanometer

Explanation: A low-resistance shunt carries most of the current around the PMMC movement, extending its range and converting it into an ammeter.

• A. Deflecting device
• B. Controlling device
• C. Damping device
• D. All of the above

Explanation: An indicating instrument needs a deflecting system to move the pointer, a controlling system to establish the final position, and a…