Electronic measurements and instrumentation miscellaneous Moderate Questions and Answers

Electronic measurements and instrumentation miscellaneous

An LVDT is used to measure displacement. The output of the LVDT is connected to a voltmeter of range 0 to 5V through an amplifier having a gain of 250. For a displacement of 0·5 mm, the output of the LVDT is 2 mV. The sensitivity of the instrument would be:

Sensitivity of LVDT =	output voltage
	displacement

=	2mV
	0·5mm

= 1V/mm.

Correct Option: C

Sensitivity of LVDT =	output voltage
	displacement

=	2mV
	0·5mm

= 1V/mm.

Wagner’s earth devices are used in ac bridge circuits to:

Wagner’s earth devices are used in ac bridge circuits to climinate the effect of earth capacitance.

Correct Option: A

Wagner’s earth devices are used in ac bridge circuits to climinate the effect of earth capacitance.

Instrument transformers are known to introduce magnitude and phase errors in measurements. These are primarily due to:

Instrument transformers are known to introduce magnitude and phase errors in measurements. These are primarly due to open and short circuit parameters of the instrument transformers.

Correct Option: C

Instrument transformers are known to introduce magnitude and phase errors in measurements. These are primarly due to open and short circuit parameters of the instrument transformers.

In a constant voltage transformer (CVT), the output voltage remains constant due to:

In a constant voltage transformer (CVT), the output voltage remains constant due to tapped windings.

Correct Option: D

In a constant voltage transformer (CVT), the output voltage remains constant due to tapped windings.

The power loss in wattmeter and energy meter instruments is more than the power loss in all ammeter and voltmeter instruments and is of the order of: