1 Answer

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

Related questions

Description : A small swamping resistance is connected in series with operating coil of a moving coil ammter in order to compensate for the effects of ____

Last Answer : temperature variation

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

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

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

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

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

Description : A moving coil of meter has 100 turns, and a length and depth of 10mm and 20mm respectively. It is positioned in a uniform radial flux density of 200 mT. The coil carrier current capacity is 50 mA. The torque on the coil is

Last Answer : A moving coil of meter has 100 turns, and a length and depth of 10mm and 20mm respectively. It is positioned in a uniform radial flux density of 200 mT. The coil carrier current capacity is 50 mA. The torque on the coil is 200µNm

Last Answer : In moving coil meters, damping is provided by eddy current disk.

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 : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:

Last Answer : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is: 0.05mA

Last Answer : The resistance in the circuit of the moving coil of a dynamometer wattmeter should be high.

Description : A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.

Last Answer : Answer :

Description : A moving coil instrument of resistance 5 Ohm requires a potential difference of 75 mV to give a full scale deflection. The value of shunt resistance needed to give a full scale deflection at 30 A is

Last Answer : A moving coil instrument of resistance 5 Ohm requires a potential difference of 75 mV to give a full scale deflection. The value of shunt resistance needed to give a full scale deflection at 30 A is 2.5 milliOhm

Description : A moving coil meter has a resistance of 3 Ω and gives full scale deflection with 30 mA. To measure voltage up to 300 V, the external resistance to be connected in series with the instrument is (A) 9997 Ω (B) 10000 Ω (C) 997 Ω (D) 10003 Ω

Last Answer : A moving coil meter has a resistance of 3 Ω and gives full scale deflection with 30 mA. To measure voltage up to 300 V, the external resistance to be connected in series with the instrument is 9997 Ω

Description : To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt

Last Answer : Answer: A

Last Answer : The multiplier and the meter coil in a voltmeter are in series.

Description : Permanent magnet moving coil instruments are used for

Last Answer : PMME are mostly used for measuring voltage and current.

Last Answer : In Weston synchronoscope the moving coil is connected across bus-bars.

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 

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

Last Answer : Dynamometer type moving coil instruments are provided with pneumatic damping

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

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

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

Description : A device used for converting A.C. into D.C. is called – (1) Transformer (2) Rectifier (3) Induction coil (4) Dynamo

Last Answer : (2) Rectifier Explanation: A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in ... -arc valves, solidstate diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.

Description : In an AC dynamo, the speed at which the coil rotates is doubled. How would this affect a) the frequency of output voltage b) the maximum output voltage?

Last Answer : a) Frequency is doubled b) Maximum output voltage is doubled.

Description : A device used for converting a.c. into d.c. is called (1) transformer (2) recticfier (3) induction coil (4) dynamo

Last Answer : recticfier

Last Answer : In a moving iron meter, the deflecting torque is proportional to Square of the current through the coil.

Last Answer : In a dynamometer 3-phase power factor meter, the planes of the two moving coils are at 120°.

Description : Explain the construction and working of moving coil instrument.

Last Answer : Construction: The moving part is a coil wound on a light aluminium frame, mounted on a shaft made of stainless steel which is pivoted at either ends on jewel bearing made of sapphire. The coil is placed between ... . Where B is magnetic flux, N is number of turns and L is length of coil. 

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

Last Answer : low resistance resistor

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

Last Answer : dc work only

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

Last Answer : because it is spring controlled

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

Last Answer : 50mA

Description : Permanent Magnet Moving Coil (PMMC) Instrument

Last Answer : Permanent Magnet Moving Coil (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.

Description : Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane

Last Answer : Answer: A

Description : A device which converts chemical energy into electrical energy is called -----? A. motor B. generator C. moving-coil meter D. battery (Answer)

Last Answer : D. battery (Answer)

Last Answer : The coil of a moving coil meter is would on An aluminium frame.

Description : The hp available at the crank shaft which is measured by a suitable dynamo meter is called 1. IMEP 2. BHP 3. Both 1 and 2 4. none of these

Last Answer : <!-- [if !supportLists] -->1.   <!-- [endif] -->ans 2  

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

Description : A 200 V, 5 A d.c. energy meter is tested at its marked ratings. The resistance of the pressure circuit is 8000 Ω and that of current coil is 0.1 Ω. The power consumed when testing the meter with phantom loading with current circuit excited by a 6 V battery is (A) 2.5 W (B) 5 W (C) 32.5 W (D) 35 W

Last Answer : A 200 V, 5 A d.c. energy meter is tested at its marked ratings. The resistance of the pressure circuit is 8000 Ω and that of current coil is 0.1 Ω. The power consumed when testing the meter with phantom loading with current circuit excited by a 6 V battery is 35 W

Description : When a resistor is used as a shunt and is connected in parallel with a meter movement coil, it will provide _____________. A. a measurement of circuit resistance B. an increased accuracy of approximately 1.5 percent C. an extended meter range D. none of the above

Last Answer : Answer: C

Description : The basic meter movement responds to the flow of current through its coil. Therefore, this meter movement may be used as a/an _____________. A. voltmeter by placing a resistance in parallel with the ... in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil

Last Answer : Answer: D

Description : A moving coil galvanometer is converted into an ammeter reads upto `0.03 A` by connecting a shunt of resistance `4r` across it and ammeter reads up `0

Last Answer : A moving coil galvanometer is converted into an ammeter reads upto `0.03 A` by connecting a shunt of resistance `4r` ... `0.02A` C. `0.03A` D. `0.04A`

Description : To send 10% of the main current through a moving coil galvanometer of resistance `99omega`, the shunt required is –

Last Answer : To send 10% of the main current through a moving coil galvanometer of resistance `99omega`, the shunt ... `11Omega` C. `10Omega` D. `9.9Omega`

Description : A multipurpose instrument for measuring current, potential difference and resistance is a) Ohmmeter b) Astatic galvanometer c) Rheostat d) AVO Meter

Last Answer : d) AVO Meter

Description :  In dynamometer type of wattmeter, which of the coil is split up into two parts?

Last Answer :  In dynamometer type of wattmeter, which of the coil is split up into two parts?  current coil

Description : The pressure coil of a dynamometer type wattmeter is  A) Highly inductive B) Highly resistive C) Purely resistive D) Purely inductive

Last Answer : highly resistive