Measurements & Instrumentation Quiz – Set 8

The dimensions of permittivity are

Bridge circuits using RTD in temperature measurement usually employ 3 lead system so as to obtain

The scale of PMMC instrument is linear.

An electrodynamometer instrument has the advantage of

Magnetic flux can be measured by

Burden of an instrument transformer is expressed in

Panel type instruments are used in

The stator of phase shifting transformer for use in conjunction with an ac potentiometer has a

In a Weston synchronoscope the deflecting torque is zero when

Figure shows the equivalent circuit of resistor. The resistor is non-inductive when

The sensitivity of a potentiometer can be increased by

Assertion (A): A radiation pyrometer is very suitable for high temperature measurement.
Reason (R): When temperature is high, a physical contact between hot body and thermometer is not desirable.

The coding system generally used in digital telemetry is

If σ is standard deviation, variation is

In low power factor wattmeter, the pressure coil is connected

Assertion (A): Megger is used to check insulation resistance of cables.
Reason (R): Insulation resistance of cables is very high.

Which of the following is not a transducer in true sense?

The adjustment of position of shading bands, in an energy meter, is done to provide

The advantage of LVDT over inductive bridge type transducer is that

In figure, the reading of wattmeter will be proportional

Assertion (A): Electrodynamic instrument is not used as ammeter or voltmeter.
Reason (R): Electrodynamic instrument is more costly than PMMC and moving iron instrument.

A moving iron instrument can be used for dc as well as ac.

Absolute instruments are used in

The advantage of semiconductor strain gauge over resistance strain gauge is

An ac bridge uses galvanometer as detector.

Assertion (A): A power factor meter operates on dynamometer principle.
Reason (R): A power factor meter does not have a control spring.

LVDT is used to measure

The multiplier resistance and meter coil in a voltmeter are in

Consider the following statements about mutual inductances:

1. The value should remain constant under all conditions.
2. The mutual inductance should not vary with temperature.
3. The inductance should be independent of excitation.
4. They have two coils wound on a bobbin of hard magnetic material, coils being separated by a range.

Out of the above, correct statement are

In semiconductor strain gauge

In a Weston synchronoscope, the moving coil is connected across

Four terminal approach is used in measuring low resistance because it

It is required to measure a low magnitude high frequency current. The proper instrument is

Assertion (A): Thermistors are commonly used to measure hot spot temperatures in electric machines.
Reason (R): Thermistor has the advantages of high temperature coefficient, small size and high speed of response.

Consider the following statements regarding phase sensitive detector

1. The detector reads zero when phases of input signal and reference signal are different.
2. The detector acts as a linear rectifier.
3 . The detector can be used as vector voltmeter.

Of the above statements which are correct?

A Q meter uses the principle of

Assertion (A): CRO can be used to study waveshape accurately.
Reason (R): Input impedance of a CRO is very high.

Which of the following can be used for measuring capacitance?

The signal to noise ratio in telemetry should be better than

Assertion (A): In a CRT, grid is kept at negative potential with respect to cathode.
Reason (R): The function of grid in an electronic tube is to control the number of electrons.

Two resistances are R₁ = 36 ± 5% and R₂ = 75 ± 5%. If they are connected in parallel, the limiting error in percent will be

Which of the following devices should be used for accurate measurement of a low dc voltage?

For measuring current at a high frequency we should use

Consider the following statements regarding electro-dynamometer type indicating instrument It can be used for measuring

1. Direct current
2. Alternating current
3. Direct voltage
5. Alternating voltage

Of these statements

In Weston synchronoscope the fixed coils are connected across

Two wattmeter method of 3-phase power measurement can be used to find

The numbers of accelerating anodes in a CRO is