1 Answer

Answer :

The reliability of the instrument refer to: Degree to which repeatability continues to remain within specified limits

Related questions

Description : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are  A) Perpendicular B) Parallel C) Inclined at 60" D) Inclined at 30°

Last Answer : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are Parallel 

Description :  In the case of an instrument reading of 8.3 V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is   (A) 1.810% (B) 0.181% (C)12.45% (D) 0.0018%

Last Answer :  In the case of an instrument reading of 8.3 V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is 12.45%

Description : A moving coil instrument has a resistance of 10 W and gives full scale deflection when carrying a current of 50 mA. To measure current upto 100 A, we will have to connect • 10 W resistance in series • 10 W resistance in parallel • 10/1999 W resistance in series • 10/1999 W resistance in parallel

Last Answer : A moving coil instrument has a resistance of 10 W and gives full scale deflection when carrying a current of 50 mA. To measure current upto 100 A, we will have to connect 10/1999 W resistance in parallel

Description : A Pyrheliometer is an instrument to measure :  (A) temperature of solar photovoltaic cell  (B) intensity of direct solar radiation at normal incidence  (C) intensity of indirect solar radiation  (D) efficiency of a solar photovoltaic cell

Last Answer : A Pyrheliometer is an instrument to measure : intensity of direct solar radiation at normal incidence 

Description : In a PMMC instrument, the damping provided is :  (A) air damping (C) eddy current damping (B) fluid damping (D) magnetic damping using a magnet

Last Answer : In a PMMC instrument, the damping provided is : eddy current damping 

Description : A PMMC instrument has FSD of 100 μA and a coil resistance of 1 kΩ. To convert the instrument into an ammeter with full scale deflection of 100 mA, the required shunt resistance is (A) 1 Ω (B) 1.001 Ω (C) 0.5 Ω (D) 10 Ω

Last Answer : A PMMC instrument has FSD of 100 μA and a coil resistance of 1 kΩ. To convert the instrument into an ammeter with full scale deflection of 100 mA, the required shunt resistance is 1.001 Ω

Description : Eddy current damping cannot be used for moving iron instrument because

Last Answer : Eddy current damping cannot be used for moving iron instrument because the presence of a permanent magnet required for such purpose would affect the deflection and hence the reading of the instrument

Description : Identify the instrument that does not exist (A) Dynamo-meter type ammeter (B) Dynamo-meter type wattmeter (C) Moving-iron voltmeter (D) Moving-iron wattmeter

Last Answer : Identify the instrument that does not exist (A) Dynamo-meter type ammeter (B) Dynamo-meter type wattmeter (C) Moving-iron voltmeter (D) Moving-iron wattmeter

Last Answer : Electrostatic instrument uses the principle of the variation of Capacitance with the voltage.

Last Answer :  In a gravity controlled instrument, the deflection angle is proportional to sine inverse of measurand.

Last Answer :  In a moving coil instrument, the deflecting torque is proportional to Current.

Last Answer : The repeat accuracy of an instrument can be judged from its standard deviation of error.

Last Answer : If the instrument is to have a wide range, the instrument should have Logarithmic scale.

Last Answer : The error of an instrument is normally given as a percentage of full-scale value.

Last Answer : An instrument to be used for measurement and control should preferably have Linear output and fast response

Last Answer : For the indicating instrument the preferred damping condition is  a damping coefficient of 0.8 to 1.

Last Answer : A moving coil instrument is used as an ohmmeter. The indicating scale of the meter will be Hyperbolic.

Last Answer : The sensitivity of an instrument is ratio of the change in the magnitude of the output to the corresponding change in the magnitude of the input.

Description :  The percentage limiting error, in the case of an instrument reading of 8.3V with a 0 to 150V voltmeter having a guaranteed accuracy of 1% full-scale reading is

Last Answer :  The percentage limiting error, in the case of an instrument reading of 8.3V with a 0 to 150V voltmeter having a guaranteed accuracy of 1% full-scale reading is 18.10%.

Last Answer : An instrument transformer is used to extend the range of induction instrument.

Last Answer : The instrument having its deflection depends upon average value is:  Rectifier type

Last Answer : Megger is an instrument used for the measurement of: High resistance and insulation resistance

Last Answer : An instrument that is capable of measuring only dc is: Moving coil

Description : PMMC instrument gives uniform scale because:

Last Answer : PMMC instrument gives uniform scale because: It uses spring control and The deflection torque is proportional to the instrument current.

Last Answer : The damping torque must operate only when the moving system of the indicating instrument is: Actually moving

Last Answer : The deflection of hot-wire instrument depends on: RMS value of the alternating current

Last Answer : In a dynamo-meter type of moving coil instrument a swamping resistance is provided inorder to: Provide equal time constant for moving coil and fixed coil, when used for ac measurement

Last Answer : A PMMC instrument can be used as a fluxmeter by: Removing the control spring

Last Answer : Hysteresis of an instrument means: The change in the same reading when input is first increased and then decreased.

Last Answer : Instrument transformers are potential transformers, current transformers.

Last Answer : The rectifier instrument is not free from frequency error.

Last Answer : A multirange instrument has multiple shunt or series resistances inside the meter.

Last Answer : The gravity controlled instrument has crowded scale because current is proportional to sine of deflection angle.

Last Answer : If an instrument has cramped scale for larger values, then it follows logarithmic law.

Description : The ratio of maximum displacement deviation to full scale deviation of the instrument is called?

Last Answer : The ratio of maximum displacement deviation to full scale deviation of the instrument is called linearity.

Last Answer : The scale of a rectifier instrument is linear.

Last Answer : A moving iron instrument can be used for both D.C. and A.C.

Last Answer : The disc of an instrument using eddy current damping should be of conducting and non-magnetic material.

Last Answer : In a portable instrument, the controlling torque is provided by spring.

Last Answer : The pointer of an indicating instrument should be very light.

Last Answer : Meggar is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another.

Last Answer : A moving-coil permanent-magnet instrument can be used as flux-meter by eliminating the control springs.

Last Answer : A moving-coil permanent-magnet instrument can be used as ammeter by using a low resistance shunt.