role of the series resistance connected in PMMC movement.

1 Answer

Answer :

A PMMC Instrument can be used as voltmeter by just connecting a series resistance with the moving coil. This series resistance is called Voltmeter Multiplier. This combination of moving coil and multiplier is connected across the point whose voltage is to be measured. There are two main function of voltmeter multiplier are 1) It limits the current through the PMMC moving coil to a value less than full scale deflection current and thus prevents moving coil from being damaged. 2) It minimizes the flow of current through the voltmeter and thus do not alter the circuit current whose voltage is to be measured. Ideally the resistance of voltmeter should be infinite

Related questions

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 : what is equivalent resistance when four 4 Ohm resistors are connected in i) series ii) parallel

Last Answer : equivalent resistance

Description : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be

Last Answer : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be 2.4 kOhm

Description : What is the total resistance if 5 resistors of 20 Ω each are connected in series? A) 100 Ω B) 4 Ω C) 20 Ω D) None of these

Last Answer : What is the total resistance if 5 resistors of 20 Ω each are connected in series? A) 100 Ω B) 4 Ω C) 20 Ω D) None of these

Description : State the use of shunt and series resistance used in extension of meter.

Last Answer : Use of shunt and series resistance: i) Use of shunt: To extend the range of Ammeter. ii) Use of series resistance: To extend the range of Voltmeter.

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.

Description : feature of PMMC instrument. 

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

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.

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.

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 : State the material used for moving coil and former for PMMC instruments. 

Last Answer : Material Used for Moving Coil and Former for PMMC Instruments:  Material used for moving coil: Copper  Material used for Former: Aluminium

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. 

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  

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 : Summerise the role of power system engineer.

Last Answer : Role of power system engineer:  i. On the planning side he or she has to make decisions on how much electricity to generate  ii. For operation of the power system he has to plan for ... for energy conservation and load management. viii. For solving the power system problems he has to update with

Description : role of tuned LC circuit in tuned amplifier.

Last Answer : In order to pick up and amplify the desired radio frequency signal, the resistive load in the audio amplifier is replaced by a tuned circuit (also called a parallel resonant circuit)as shown ... desired radio frequency signal. (ii)Amplification of the selected signal to a suitable voltage level.

Description : What is your country doing in order to shift towards more green energy?

Last Answer : answer:I just found this info for my state. www.green.ca.gov I have lived on rural properties for years that are chemical and pesticide free and wildlife havens. I am going to visit an 8 ... . I would be recycling and composting almost everything again after the last 15 months in city hell. haha

Description : Is there a story behind how chess men move?

Last Answer : answer:According to the United States Chess Federation, the game of chess started in India. Others argue that it began thousands of years before. Whatever its origin, the game has always pinned two ... Way They Do? | eHow.com http://www.ehow.com/about_5367497_do-pieces-move-way-do.html#ixzz12MJM2zcw

Description : Why when you are high in the sky and looking from the window of an airplane, it seemed that it moves very slowly, but when starting to lose altitude to land, suddenly it feels that it moves much faster?

Last Answer : The farther you are from something, the slower it appears to move. The closer you are to something, the faster it appears to move. This probably has something to do with relative frames of reference.

Description : What's the difference between a Village and a Tribe?

Last Answer : Tribe – people. Village – structures.

Description : The 22nd of Bahman: what will happen in Iran?

Last Answer : Well if it is true about them hitting the magic 20% of enriched uranium & it’s a big if,then the shit will probably hit the fan anytime soon.

Description : Is there an analog stick attachment/accessory for the Nintendo DS Lite?

Last Answer : No the only thing in the box is ds, 2 pens, instruction booklet thats all

Description : What's with the lights/colors/motion you see when you close your eyes?

Last Answer : How much have you been smoking, pete?

Description : An inductor is connected in series with SCR to protect it from A) Excessive high voltage B) Excessive high dv/dt C) Excessive high di/dt D) Excessive large forward current 

Last Answer : An inductor is connected in series with SCR to protect it from Excessive high di/dt

Description : Two 100W, 200V lamps are connected in series across a 200V supply. The total power consumed by each lamp will be in Watts

Last Answer : 4800

Description : A DC voltage source is connected across a series RLC circuit. Under steady-state conditions, the applied DC voltage drops entirely across the

Last Answer : A DC voltage source is connected across a series RLC circuit. Under steady-state conditions, the applied DC voltage drops entirely across the C only

Description : Consider a circuit with four resistors in series connected to a voltage source. What happens to the voltage across each resistor, if the value of each of the resistors is doubled? A) It will double B) It will remain the same C) It will be halved D) It will become zero

Last Answer : Consider a circuit with four resistors in series connected to a voltage source. What happens to the voltage across each resistor, if the value of each of the resistors is doubled? A) It will double B) It will remain the same C) It will be halved D) It will become zero

Description : A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will?

Last Answer : A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will increase.

Description : Two resistances Rl and Ri are connected in series across the voltage source where Rl>Ri. The largest drop will be across?

Last Answer : Two resistances Rl and Ri are connected in series across the voltage source where Rl>Ri. The largest drop will be across Rl.

Description : Two resistors are said to be connected in series when?

Last Answer : Two resistors are said to be connected in series when same current passes in turn through both.

Last Answer : When two D.C. series motors are connected in parallel, the resultant speed is normal speed.

Last Answer : In a A.C. series motor armature coils are usually connected to commutator through resistance.

Last Answer : When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.

Description : Cells are connected in series in order to?

Last Answer : Cells are connected in series in order to increase voltage available.

Description : When the voltage across a battery is measured using a D.C potentiometer, the reading shows 1.08 V. But when the same voltage is measured using a Permanent Magnet Moving Coil (PMMC) voltmeter, the voltmeter reading shows 0.99 ... resistance of the battery, in Ohm , is (A) 150 (B) 100 (C) 50 (D) 200

Last Answer : When the voltage across a battery is measured using a D.C potentiometer, the reading shows 1.08 V. But when the same voltage is measured using a Permanent Magnet Moving Coil (PMMC) voltmeter, ... resistance of the voltmeter is 1100 Ohm , the internal resistance of the battery, in Ohm , is 100

Description : If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be?

Last Answer : 0.1s

Description : Will you watch the new series Ash vs the Evil Dead?

Last Answer : Hail to the king, baby.

Description : Why is the Twilight series so famous?

Last Answer : I haven't read them but my wife is completely addicted to them. She's read the books several times and seen the movie probably 6 or 7 times, going with different people. Her 45 year old aunt loves them ... just fall in love with that guy. I don't know. It's definitely not limited to teens though.

Description : State the modification to be done in dc series motor to work satisfactorily as ac series motor. State applications of ac series motor.

Last Answer : Modifications are necessary in a dc series motor so that it operates satisfactorily on ac supply. The modifications are as follows:  1) AC series motor is built with a few field turns as ... and grinders 5) High speed vacuum cleaners 6) Sewing machines 7) Food processors 8) Drilling machine 

Description : Explain with neat diagram series and parallel magnetic circuits. 

Last Answer : Series magnetic circuit: When different magnetic materials having different lengths, cross sectional areas and permeability are connected one after another, in which same flux is established in different sections, then it is called series ... flux, Φ = Φ1 + Φ2  Path 1: BAFE  Path 2: BACD

Description : Write two applications of D.C. series motor. 

Last Answer : The applications of D.C. series motor: 1. Cranes 2. Hoists 3. Trolley and cars 4. Conveyors 5. For traction work i.e. electric locomotives 6. Elevator 7. Air compressor

Description : Brake test on DC series motor

Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

Description : The loop equation for a series RLC circuit gives

Last Answer : The loop equation for a series RLC circuit gives

Description : Series parallel resistances problem solution

Last Answer : Series parallel resistances problem solution

Description : Source transformation Replace the circuit with voltage source in series with a single resistor

Last Answer : Source transformation Replace the circuit with voltage source in series with a single resistor

Description : Series rc circuits

Last Answer : Series rc circuits

Description : Series circuit rules

Last Answer : Series circuit rules

Description : X L and X C in Series

Last Answer : Inductive reactance X L and Capacitive reactance X C in series. Inductive reactance X L of value 60 ohm and Capacitive reactance X C of value 40 ohm are connected in series. 120 volts A C voltage is ... . The current will be 6 ampere. This time current will lead the voltage by 90 degree.

Description : Series and parallel capacitor problem

Last Answer : Series and parallel capacitor problem 1 : https://youtu.be/MSl5mRwtjAE Series and parallel capacitor problem 2 : https://youtu.be/yGwbpyEtIyw Series and parallel capacitor problem 3 : https:// ... https://youtu.be/_7KwEwWqiNU Series and parallel capacitor problem 10 : https://youtu.be/et8MCWV_OyE

Description : Describe the reason of using dc series motor for electric trains.

Last Answer : Electric trains require an inverse torque speed characteristics for proper operation. That is a higher torque is required at start (when speed is nil or low) and as the train picks up ... torque - speed characteristics of DC series motors match, these motors are suitable for electric trains