Basically, a PMMC instrument can be used only in

Basically, a PMMC instrument can be used only in
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Answer :

dc measurements
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Related questions

Another name for PMMC instrument

Description : Another name for PMMC instrument

Last Answer : D'Arsonval

Controlling torque in PMMC

Description : Controlling torque in PMMC

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A dynamometer instrument is mainly used as a/an

Description : A dynamometer instrument is mainly used as a/an

Last Answer : wattmeter

An instrument of device having recognized permanent of stable value that is used as a reference.

Description : An instrument of device having recognized permanent of stable value that is used as a reference.

Last Answer : standard instrument/device

The scale of a hot-wire instrument is a/an ___function

Description : The scale of a hot-wire instrument is a/an ___function

Last Answer : squared

Moving-iron instrument has a/an scale

Description : Moving-iron instrument has a/an scale

Last Answer : squared

What is an electronic instrument capable of showing on screen and maybe on print, relative spacing of transmitter carriers, their sidebands and harmonics?

Description : What is an electronic instrument capable of showing on screen and maybe on print, relative spacing of transmitter carriers, their sidebands and harmonics?

Last Answer : Spectrum Analyzer

A device or instrument, which delivers signals of precise frequency and amplitude, usually over a wide range

Description : A device or instrument, which delivers signals of precise frequency and amplitude, usually over a wide range

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When both deflecting and controlling torque act, the pointer of an indicating instrument comes to

Description : When both deflecting and controlling torque act, the pointer of an indicating instrument comes to

Last Answer : rest

The smallest change in a measured variable to which an instrument will respond.

Description : The smallest change in a measured variable to which an instrument will respond.

Last Answer : resolution

In RF and microwave system, what instrument is used to measure the incidental and reflected signals?

Description : In RF and microwave system, what instrument is used to measure the incidental and reflected signals?

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This instrument measures temperatures by electric means, especially temperatures beyong the range of mercury thermometers

Description : This instrument measures temperatures by electric means, especially temperatures beyong the range of mercury thermometers

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Which instrument is the most sensitive?

Description : Which instrument is the most sensitive?

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A device or instrument able to generate noise with accurate voltage for test purposes

Description : A device or instrument able to generate noise with accurate voltage for test purposes

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Description : Resistance measuring instrument particularly used in determining the insulation resistance

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What is that instrument used for measuring the strength and direction of magnetic fields?

Description : What is that instrument used for measuring the strength and direction of magnetic fields?

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Majority of analog measuring instrument utilizes one of the following effects.

Description : Majority of analog measuring instrument utilizes one of the following effects.

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Current range extension in moving coil instruments can be achieved by placing a ___ in shunt with the instrument.

Description : Current range extension in moving coil instruments can be achieved by placing a ___ in shunt with the instrument.

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Determine which is not a dynamic instrument

Description : Determine which is not a dynamic instrument

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What do you call of an instrument that depends for its operation on the reaction between magnetic flux set up by currents in fixed windings and other currents set up by electromagnet induction in movable conducting parts?

Description : What do you call of an instrument that depends for its operation on the reaction between magnetic flux set up by currents in fixed windings and other currents set up by electromagnet induction in movable conducting parts?

Last Answer : induction instrument

As the deflection of the moving system increases, the controlling torque in an indicating instrument.

Description : As the deflection of the moving system increases, the controlling torque in an indicating instrument.

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An electro pyrometer is an instrument used to measure?

Description : An electro pyrometer is an instrument used to measure?

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An instrument used to detect and measure the presence of electrical current is generally called

Description : An instrument used to detect and measure the presence of electrical current is generally called

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An indicating instrument whose movable coils rotate between two-stationary coils, usually used as wattmeter

Description : An indicating instrument whose movable coils rotate between two-stationary coils, usually used as wattmeter

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Description : A tunable RF instrument, which, by means of a sharp dip of an indicating meter, indicates resonance with an external circuit under test

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Permanent-magnet moving coil instrument can be used in

Description : Permanent-magnet moving coil instrument can be used in

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A force in analog instrument which quickly brings the moving system to rest in its final position.

Description : A force in analog instrument which quickly brings the moving system to rest in its final position.

Last Answer : damping force

If the pointer of an indicating instrument is in motion, then what opposes deflecting torque?

Description : If the pointer of an indicating instrument is in motion, then what opposes deflecting torque?

Last Answer : damping and controlling torque

What is the force acting on the pointer of an indicating instrument when it is in motion?

Description : What is the force acting on the pointer of an indicating instrument when it is in motion?

Last Answer : controlling, damping and deflecting torques

What is this instrument or circuit that has four or more arms, by means of which one or more of the electrical constance of an unknown component may be measured?

Description : What is this instrument or circuit that has four or more arms, by means of which one or more of the electrical constance of an unknown component may be measured?

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Dynamometer type instrument can be used for

Description : Dynamometer type instrument can be used for

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What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Description : What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Last Answer : because it is spring controlled

Indicating instrument is assumed to be most accurate at what part of the scale?

Description : Indicating instrument is assumed to be most accurate at what part of the scale?

Last Answer : at half or full

An instrument in which the magnitude of the measured quantity is indicated by means of pointer.

Description : An instrument in which the magnitude of the measured quantity is indicated by means of pointer.

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What type of instrument is the watt-hour meter?

Description : What type of instrument is the watt-hour meter?

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What kind of instrument is an ammeter?

Description : What kind of instrument is an ammeter?

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An instrument used for measuring the amount of current flowing in a circuit.

Description : An instrument used for measuring the amount of current flowing in a circuit.

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The pointer of an indicating instrument is generally made of

Description : The pointer of an indicating instrument is generally made of

Last Answer : aluminum

What is the typical full-scale deflection current of a moving coil instrument?

Description : What is the typical full-scale deflection current of a moving coil instrument?

Last Answer : 50mA

Derive the relation for deflection torque in PMMC instrument.

Description : Derive the relation for deflection torque in PMMC instrument. 

Last Answer : Ans: The length of coil be l meter and width of coil be d meter. Assume I is the current flowing in the ciol having N turns. Assume B as the flux density in the air gap then F=BIL ... a direct indication of the current in the coil. The pointer deflection can therefore be used to measure current.

Draw the diagram of PMMC instrument and state the deflection torque equation

Description : Draw the diagram of PMMC instrument and state the deflection torque equation

Last Answer : Equation Ʈ= B*A*I*N Where r= torque Newton. Meter B = flux density in the air gap. Wb/m2 A = effective coil area (m) N= number of turns of wire of the coil

List two advantages of PMMC instrument.

Description : List two advantages of PMMC instrument.

Last Answer : 1. It has uniform scale. 2. Power consumption is low 3. It can be obtained in wide ranges. 4. High sensitivity & accuracy 5. It is unaffected by external magnetic field. 6. Additional damping device not required. 7. Hysteresis problem is not there.

Permanent Magnet Moving Coil (PMMC) Instrument

Description : Permanent Magnet Moving Coil (PMMC) Instrument

Last Answer : Permanent Magnet Moving Coil (PMMC) Instrument

State the working principle of PMMC Analog instrument.

Description : State the working principle of PMMC Analog instrument.

Last Answer : Working Principal of PMMC Analog Instrument: When current carrying conductor is placed in a magnetic field, it experiences mechanical force. In PMMC instrument, when current flows through a coil ... coil rotates and pointer attached to the coil shows deflection proportional to the current magnitude.

feature of PMMC instrument.

Description : feature of PMMC instrument. 

Last Answer : Consumes less power Great accuracy. High torque to weight ratio

State the function of former and control spring in PMMC instrument.

Description : State the function of former and control spring in PMMC instrument.

Last Answer : Function of Former: To support the coil and provide eddy current damping.  Function of Control Spring: To provide control torque or force and in some instruments springs can be used as current leads.

‘PMMC instrument is not suitable to measure AC quantity’. State the reason.

Description : ‘PMMC instrument is not suitable to measure AC quantity’. State the reason.

Last Answer : The direction of force exerted on moving coil depends on the direction of current flowing through moving coil. If the direction of magnetic field is kept constant, it produces unidirectional torque if the current is ... on the coil in one cycle to zero. Hence the meter cannot read A.C. quantities.

Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Description : Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Last Answer : (i) Material used for Moving coil: Copper, Aluminum( some times)  (ii) Permanent magnets are made of special alloys such as :  Aluminum-Nickel-Cobalt (Alnicos)  Strontium-Iron  Neodymium-Iron-Boron  Samarium-Cobalt.

State working principle of PMMC instrument.

Description : State working principle of PMMC instrument.

Last Answer : Working Principle of PMMC Instrument: When current carrying conductor is placed in a constant magnetic field, it experiences a force proportional to the current and produces proportional deflection torque. 

Compare PMMC & MI instrument.

Description : Compare PMMC & MI instrument.

Last Answer : MI Instrument  PMMC Instrument  It works on the principles of magnetism.  It works on the principle of DC motor Deflection torque is proportional to square of current  Deflection ... , Voltmeter and Watt meter  Can be used as voltmeter, Ammeter, Galvanometer, ohmmeter