Sunday, October 19, 2014

Measurements Instrumentation Objective Questions Answers: Part-7

Measurements Instrumentation Objective Questions with Answers

[1] A mulliammeter can be used as
(a) Voltmeter and ammeter
(b) Wattmeter
(c) Ohmmeter
(d) Frequency meter


[2] Which instrument has identical calibration for ac as well as dc values?
(a) Hot wire type
(b) Moving coil type
(c) Induction type
(d) Moving iron type


[3] An instrument to be used for measurement and control should preferably have
(a) Dead zone and dead time
(b) Linear output and fast response
(c) Non-linear output
(d) A highly damped response


[4] The current coil of a wattmeter is connected to the CT of R-phase. The potential coil is connected across Y and B phases. The wattmeter measures
(a) Active power in R phase
(b) Active power of Y phase
(c) Reactive power of R phase
(d) Power proportional to 3 phase power if the load is balanced


[5] The problem of Electro-static coupling in a transformer is acute at
(a) Low frequencies
(b) Power frequencies
(c) High frequencies
(d) High load on the transformer


[6] Which meter is suitable for the measurement of 10mV at 50MHz?
(a) Moving iron voltmeter
(b) VTVM
(c) Moving coil voltmeter
(d) CRO


[7] It can be stated that
(a) CT operates at almost the same flux density as a PT
(b) CT operates with a higher flux density than PT
(c) CT operates with considerably lower flux density than a PT
(d) no generalisation can be made with regard to the flux densities in CT and PT


[8] The thermocouple instruments do not have
(a) High sensitivity
(b) Absence of frequency error
(c) Independence of ambient temperature
(d) High degree of measuring accuracy


[9] Some wire- wound resistors have bifilar winding. This type of winding is used to
(a) Increase the thermal stability
(b) Reduce the tolerance
(c) Reduce the inductance of winding
(d) Double the power rating of the resistor


[10] Wien bridge is useful for measuring
(a) Very high frequency
(b) Low frequency
(c) Medium frequency
(d) High frequency


[11] A megger is usually
(a) Moving iron type instrument
(b) Electro-static type instrument
(c) Hot-wire type instrument
(d) Moving coil type instrument


[12] A moving iron ammeter may be compensated for frequency errors by
(a) a shunt resistance
(b) a series inductance
(c) shunt capacitance
(d) series resistance


[13] Ryall crest voltmeter is used for measurement of
(a) AC voltage of any form
(b) Low frequency voltage
(c) High DC voltage
(d) High AC voltage


[14] Jewels are used in instruments for the purpose of
(a) Damping
(b) Torque control
(c) Suppressing noise
(d) Bearing


[15] The thermocouple instrument will measure
(a) Current
(b) Voltage
(c) Flux
(d) None of the above
9:11 AM