1 Answer

Answer :

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

Related questions

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. 

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

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 : 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 : 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 : 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 : 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 produced in wattmeter is proportional to

Last Answer : A

Description : Portable Cement Mixers

Last Answer : Portable concrete mixers, just like other concrete mixers, come in various styles. One type of portable concrete mixer is one that has to be transported to a job site. The concrete mix then has to be ... yard or specific location much easier, allowing you to pour and mix the cement at your own pace.

Description : Mini Portable Cement Mixers

Last Answer : Have you ever wondered if there is an easier way to do small cement mixing jobs? Have you ever considered finding a more efficient way to make a small amount of concrete, mortar plaster or another type ... adjustable hitches so that it can pour out of the cart and onto the spot that is being poured.

Description : How to Make a Portable Water Purifier

Last Answer : Having a portable purifier at home ensures that you and your family are drinking clean, microbe-free water. Just by running tap water onto the apparatus, it enacts on the liquid, filtering ... an assurance of good health. For more information regarding this article, read how to purify water.

Description : Where are portable screw compressors used?

Last Answer : Where are portable screw compressors used? The use of a portable screw air compressor in road, construction, mining and installation works indicates that its area of practical use is ... with these important, but fairly simple requirements will significantly lengthen the life of your compressor.

Last Answer : The electric motor used in portable drills is universal motor.

Description : A Pyrheliometer is an instrument to measure :  (A) temperature of solar photovoltaic cell  (B) intensity of direct solar radiation at normal incidence  (C) intensity of indirect solar radiation  (D) efficiency of a solar photovoltaic cell

Last Answer : A Pyrheliometer is an instrument to measure : intensity of direct solar radiation at normal incidence 

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 : 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 : 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 : Instrument transformers are potential transformers, current transformers.

Last Answer : The rectifier instrument is not free from frequency error.

Last Answer : A multirange instrument has multiple shunt or series resistances inside the meter.

Last Answer : The gravity controlled instrument has crowded scale because current is proportional to sine of deflection angle.

Last Answer : If an instrument has cramped scale for larger values, then it follows logarithmic law.

Description : The ratio of maximum displacement deviation to full scale deviation of the instrument is called?

Last Answer : The ratio of maximum displacement deviation to full scale deviation of the instrument is called linearity.

Last Answer : The scale of a rectifier instrument is linear.

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

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

Last Answer : The pointer of an indicating instrument should be very light.

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

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

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

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 : List the different methods to produce damping torque.

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

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 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 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 : 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.

Last Answer : The ratio of starting torque to full-load torque is least in case of shunt motors.

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.

Last Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Last Answer : The torque produced in induction type relay (shaded pole structure) is inversely proportional to the square of the current.