List the different methods to produce damping torque.

1 Answer

Answer :

Methods of providing damping torque in indicating type instruments: 1) Air friction damping. 2) Fluid friction damping. 3) Eddy current damping.

Related questions

Description : Ideally, the damping torque should be  (1) Proportional to velocity of the moving system and operating current.  (2) Proportional to the velocity of the moving system but independent of operating ... operating current.  (4) Independent of the velocity of the moving system and operating current.

Last Answer : Ideally, the damping torque should be Proportional to the velocity of the moving system but independent of operating current. 

Description : List the different level measurement methods. 

Last Answer : Liquid Level Measurement Direct method 1. Hook type 2. Sight glass gype 3. Float type 4. Dip stick Indirect method 1. Hydraustatic pressure type 2. Electrical type a) Capacitance level indicator b) Radiation level detector c) Ultrasonic level gauge 3. Radar type

Description : List different starting methods of three phase synchronous motor. Explain any one of them.

Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor. 

Description : State the different methods of Power Generation adopted in India. 

Last Answer : 1. Hydro energy or hydro Electric power plant  2. Nuclear energy or nuclear Power Plant  3. Fossil fuels: i) Thermal energy (by combustion of coal) or Thermal Power Plant ii) Natural gas ... from any organic waste materials. It contains mixture of methane(50-65 % in volume) and carbon dioxide

Description : How are nuclear reactors controlled? Explain two different methods in brief.

Last Answer : Nuclear reactor is controlled using control rods: Control rods are made up of very high neutron absorbing material like boron, cadmium. By adjusting height of control rods on reactor core ... of nuclear reaction will increase. Whereas by pushing control rod towards the core it will reduce.

Description : Name the different torque and their function in measuring instrument.

Last Answer : List of torques in analog instruments:  1. Deflecting torque  2. Controlling / restraining torque.  3. Damping torque.  1. Deflecting torque:  - To create deflection of pointer ... .  - Bring the pointer to standstill quickly.  - To minimize oscillations about final position. 

Description : What states produce is the best?

Last Answer : Florida citrus is incredible. Florida oranges make a great snack and an incredible juice. I wish everyone had a chance to taste one picked fresh from the tree.

Description : Describe with neat diagram air friction damping. 

Last Answer : Air Friction Damping: Here air trapped in the chamber works as damping medium for the piston movement connected to the spindle. The piston moves in the air chamber. The clearance between piston and ... will be the damping torque, bringing the pointer to the equilibrium position quickly. 

Description : Given a unity feedback system with G(s)=k/s (s+4), the value of k for damping ratio of 0.5 is

Last Answer : Given a unity feedback system with G(s)=k/s (s+4), the value of k for damping ratio of 0.5 is 16

Description : A control system having unit damping factor will give  (1) Oscillatory response (2) Undamped response (3) Critically damped response (4) No response

Last Answer : 1

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 : 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 : The damping factor of a particular system is unity, the system response will be

Last Answer : The damping factor of a particular system is unity, the system response will be critically damped

Last Answer : Damping of the Ballistic galvanometer is made small to get first deflection large.

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

Last Answer : In the majority of instruments, damping is provided by eddy currents.

Description : The damping winding in synchronous motor is generally used to?

Last Answer : The damping winding in synchronous motor is generally used to provide starting torque and prevent hunting.

Description : List any two methods of reactive power measurement in 3 phase circuit.

Last Answer : Methods of reactive power measurement in 3 phase circuit: (i) Two single phase wattmeter method (ii) One single phase wattmeter method

Description : List various transistor biasing methods.

Last Answer : Types of biasing methods: i. Base bias (or fixed bias) ii. Base bias with emitter feedback. iii. Base bias with collector feedback iv. Voltage divider bias (or self bias) v. Emitter bias. 

Description : Name two methods for measurement of low, medium and high resistance. Give one advantage and one limitation of V- I method.

Last Answer : Methods for measurement of low resistance:  1. Ammeter voltmeter method  2. Kelvin's bridge method  3. Ohm meter method  4. Potentiometer method  5. Digital/analog multi-meter ... must be infinity for perfectly accurate measurement which is not possible.  2. Connection errors.

Description : Describe spring control method of producing controlling torque in measuring instrument. Write any two properties required for spring material.

Last Answer : A)Spring control method: As shown in the figure, the inner ends of the both springs are attahced to the spindle, while outer end of upper spring is attached to the lever and outer ... of spring material: 1.Non Magnetic material 2.Low specific resistance 3.Low temperature coefficient of resistance

Description : State the function of controlling torque in electrical measuring instrument.

Last Answer : Function of controlling torque  1. The function is to opposes the deflection force and increases with the increase in the deflection of the moving system, to limit its movement. 2. and brought ... set a position where the two opposing forces i.e. deflection and controlling forces are equal. 

Description : State the function of controlling torque. Write two types of it.

Last Answer : Function of Controlling Torque:  To restrict the motion of pointer / spindle and stop the pointer at the relevant position to get correct reading.  To bring back pointer to zero ... measurement is removed.  Types of Controlling Torque: 1. Spring control method 2.Gravity control method 

Description : Why a dc series motor has a high starting torque?

Last Answer : motor

Description : List the four different units of pressure.

Last Answer : Different units of pressure. 1) Measured in pascal(Pa). 2) Measured in pounds per square inch(psi) 3) Measured in kilogram per square of centimeter (Kg/cm2 ). 4) Measured in newton per square meter (N/m2 ). 5) Measured in terms of liquid columns. mmHg or mmWc

Description : List the different types of frequency meters.

Last Answer : Different types of frequency meters  1. Reed type [Mechanical type] 2. Ferro-dynamic type [Resonances type] 3. Weston type 4. Ratio-meter type 5. Saturable core type 6. Digital type

Description : List the different errors in wattmeter & explain compensation for it.

Last Answer : Errors in Wattmeter Compensation method Error due to connection method To overcome this error, wattmeters are provided with additional compensating winding which is connected in series with ... due to friction The weight of moving system be reduced to minimum possible.

Description : List different types of FET.

Last Answer : Types of FETs:  1. Junction FET (JFET) i. N-Channel JFET ii. P-Channel JFET  2. MOSFET i. E-MOSFET ii. D-MOSFET 

Description : What are your methods for dealing with unwarranted not to say unwanted attention from a drunk?

Last Answer : answer:I interact briefly, and loudly, eg YES, IT IS A NICE DRESS ISN'T IT? as I firmly walk away Or, if I am not in a situation where I can't walk away, I just give a half- ... ha ha! I am someone that makes eyecontact with people, and generally quite smiley so I guess I must seem approachable!

Description : State the various lighting calculations methods and Describe any one of them.

Last Answer : Lighting calculation methods: 1. Lumens or Light flux method 2. Point to point or Inverse Square law method 3. Watts per Square meter method i) Lumens or Light ... is taken according to the illumination desired on an average value considering overall efficiency of the lighting system.

Description : Describe the following energy conservation methods of lighting system. i) By replacing lamp sources ii) Using light control gears.

Last Answer : Energy conservation methods of lighting system:  i) By replacing lamp sources:  Installation of energy efficient fluorescent lamps in place of Conventional fluorescent lamps. Installation of ... (HF) electronic ballasts in place of conventional ballasts which saves energy up to 35%.

Description : Describe the following energy conservation methods of electrical motor. i) By motor survey ii) By matching loads with motor rating

Last Answer : Energy conservation methods of electrical motor:  1) By Motor Survey: Large industries have a massive population of LT motors. Load survey of LT motors can be taken-up methodically to ... -speed motors, eddy-current couplings, fluid couplings, and solid-state electronic variable speed drives.

Description : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods :  (A) Butt welding and Seam welding  (B) Hydrogen shielding and Projection welding  (C) Seam welding and Coated electrode welding  (D) Coated electrode welding and Hydrogen shielding

Last Answer : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods :  (A) Butt welding and Seam welding  (B) Hydrogen shielding and Projection welding  ... Seam welding and Coated electrode welding  (D) Coated electrode welding and Hydrogen shielding

Description : What are the speed control methods of dc motor?

Last Answer : Field control of DC motor Armature control of DC motor

Description : DC motor gross torque example

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 : In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.

Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.

Description : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be

Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m

Description : Torque angle for the synchronous machine is the angle between (A) stator magnetic field and rotor magnetic field (B) stator magnetic field and net magnetic field in the air gap (C) rotor magnetic field and net magnetic field in the air gap (D) excitation voltage and impedance voltage drop

Last Answer : Torque angle for the synchronous machine is the angle between rotor magnetic field and net magnetic field in the air gap

Description : The meter which does not have any component in it to provide control torque is (A) Electrodynamometer for current measurement (B) Electrodynamometer for voltage measurement (C) Electrodynamometer for power measurement. (D) Electrodynamometer for power factor measurement.

Last Answer : The meter which does not have any component in it to provide control torque is Electrodynamometer for power factor measurement.

Description : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down

Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque

Description : The torque produced in wattmeter is proportional to

Last Answer : A

Description : The shaft torque of a d.c. motor is less than its armature torque because of .......... losses.

Last Answer : The shaft torque of a d.c. motor is less than its armature torque because of rotational losses.

Description : The maximum torque of d.c. motors is limited by?

Last Answer : The maximum torque of d.c. motors is limited by commutation.

Last Answer : In a meggar controlling torque is provided by coil.

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

Last Answer : Torque developed by a D.C. motor depends upon magnetic field, active length of the conductor, current flow through the conductors, number of conductors, radius of armature.

Last Answer : For constant torque drive armature voltage control speed control method is preferred.

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.

Last Answer : Buses, trains, trolleys, hoists, cranes require high starting torque and therefore make use of D.C. series motor.

Last Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.