Air friction damping is used in the instruments which is:

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Answer :

Air friction damping is used in the instruments which is: Moving iron

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Eddy current damping is normally used in the instruments of

Description : Eddy current damping is normally used in the instruments of (a) Induction type (b) Moving iron type (c) Permanent magnet moving coil type (d) Nothing can be said 

Last Answer : Permanent  magnetic  moving  coil  instrument.

In majority of instruments damping is provided by?

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

Describe with neat diagram air friction damping.

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. 

In moving iron instruments, eddy current damping cannot be used as

Description : In moving iron instruments, eddy current damping cannot be used as  (a) They have a strong operating magnetic, field (b) They are not normally used in vertical position (c) They ... of a permanent magnet required for eddy current damping would distort the existing weak operating magnetic field

Last Answer : In moving iron instruments, eddy current damping cannot be used as The introduction of a permanent magnet required for eddy current damping would distort the existing weak operating magnetic field

The best and efficient damping in Analog instruments is : -

Description : The best and efficient damping in Analog instruments is : - a) Air Friction damping b) Fluid Friction damping c) Eddy Current damping d) None of the above

Last Answer : The best and efficient damping in Analog instruments is : - Eddy Current damping

Control systems are generally designed with damping

Description : Control systems are generally designed with damping  a) less than one  b) greater than one c) equal to one d) with any value depending upon system requirement

Last Answer : Control systems are generally designed with damping  less than one 

A control system having unit damping factor will give

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

Ideally, the damping torque should be

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. 

In a PMMC instrument, the damping provided is :

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 

Eddy current damping cannot be used for moving iron instrument because

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

For the indicating instrument the preferred damping condition is

Last Answer : For the indicating instrument the preferred damping condition is  a damping coefficient of 0.8 to 1.

In moving coil meters, damping is provided by

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

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

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

Damping of the Ballistic galvanometer is made small to?

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

The disc of an instrument using eddy current damping should be of?

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

Eddy current damping is an example of _____ A Coulomb damping B Hysteresis damping C Viscous damping D Dry friction damping

Description : Eddy current damping is an example of _____ A Coulomb damping B Hysteresis damping C Viscous damping D Dry friction damping

Last Answer : C Viscous damping

Eddy current damping is an example of _____A. Coulomb damping B. Hysteresis damping C. Viscous damping D. Dry friction damping

Description : Eddy current damping is an example of _____A. Coulomb damping B. Hysteresis damping C. Viscous damping D. Dry friction damping

Last Answer : C. Viscous damping

Eddy current damping is an example of _____ A) Coulomb damping B) Hysteresis damping C) Viscous damping D) Dry friction damping

Description : Eddy current damping is an example of _____ A) Coulomb damping B) Hysteresis damping C) Viscous damping D) Dry friction damping

Last Answer : C) Viscous damping

Eddy current damping is an example of _____ a. Coulomb damping b. Hysteresis damping c. Viscous damping d. Dry friction damping

Description : Eddy current damping is an example of _____ a. Coulomb damping b. Hysteresis damping c. Viscous damping d. Dry friction damping

Last Answer : c. Viscous damping

Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body 3. For smooth surfaces, coefficient of friction depends upon velocity 4. Damping force depends upon the rubbing velocity between two rubbing surfaces a. Only statement 1 b. Statement 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true

Description : Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body ... 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true

Last Answer : c. Only statement 2

Reduction in vibration amplitude after one complete cycle of single degree free vibration with dry friction damping is_____, if where F"= frictional force between mass and surface and k =stiffness of the system. a)4F/k a b) 2f/K C) 3F/k D)8F/k

Description : Reduction in vibration amplitude after one complete cycle of single degree free vibration with dry friction damping is_____, if where F"= frictional force between mass and surface and k =stiffness of the system. a)4F/k a b) 2f/K C) 3F/k D)8F/k

Last Answer : a)4F/k

Which of the following instruments can be used for measurement of very high value resistances such as

Description : Which of the following instruments can be used for measurement of very high value resistances such as insulation resistance in industries? A) Wheatstone bridge B) Megger C) Ohm-meter D) Resistive potentiometer 

Last Answer : Which of the following instruments can be used for measurement of very high value resistances such as insulation resistance in industries? A) Wheatstone bridge B) Megger C) Ohm-meter D) Resistive potentiometer 

Highest flux density exists inside which of the following instruments?

Description :  Highest flux density exists inside which of the following instruments? A) Electrodynamic instruments B) Hot wire instruments C) Moving iron instruments D) Moving coil instruments

Last Answer : Highest flux density exists inside which of the following instruments? A) Electrodynamic instruments B) Hot wire instruments C) Moving iron instruments D) Moving coil instruments 

The type of instruments used mainly for standardizing instruments in laboratories is

Description : The type of instruments used mainly for standardizing instruments in laboratories is (a) Indicating instrument (b) Integrating instrument (c) Absolute instrument (d) Recording instrument  

Last Answer : Ans:Option C

Electrostatic type instruments are primarily used as

Description : Electrostatic type instruments are primarily used as 

Last Answer : Voltmeter

The force required to move the pointer in an indicating instruments is

Description : The force required to move the pointer in an indicating instruments is

Last Answer : The force required to move the pointer in an indicating instruments is deflecting force

Horizontally mounted moving iron instruments use

Description : Horizontally mounted moving iron instruments use   (a) Eddy current damping (b) Electromagnetic damping (c) Fluid friction damping (d) Air friction damping

Last Answer : Horizontally mounted moving iron instruments use Air friction damping

Permanent magnet moving coil instruments are used for

Description : Permanent magnet moving coil instruments are used for

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

Thermocouple instruments are also known as

Last Answer : Thermocouple instruments are also known as Rectifier instruments.

PMMC type instruments normally use

Last Answer : PMMC type instruments normally use Eddy current damping.

Electrostatic instruments are normally used for

Last Answer :  Electrostatic instruments are normally used for High voltage measurements.

Which of the following instruments can be used to measure AC current only?

Description : Which of the following instruments can be used to measure AC current only? (a) Permanent Magnet Type ammeter(b) Induction type ammeter (c) Moving iron voltmeter(d) Moving iron ammeter

Last Answer : (b) Induction type ammeter

Jewels are used in instruments for the purpose of

Last Answer : Jewels are used in instruments for the purpose of Bearing.

The thermocouple instruments do not have

Last Answer : The thermocouple instruments do not have High degree of measuring accuracy.

In the case of PMMC rectifier type instruments, the deflecting torque is proportional to

Last Answer : In the case of PMMC rectifier type instruments, the deflecting torque is proportional to Average value of AC current.

The electrostatic instruments can be used without serious loss of accuracy upto ......... frequency

Last Answer : The electrostatic instruments can be used without serious loss of accuracy upto 100kHz frequency.

_____ instruments are those which measure the total quantity of electricity delivered in a particular time.

Last Answer : Integrating instruments are those which measure the total quantity of electricity delivered in a particular time.

The use of _____ instruments is merely confined within laboratories as standardising instruments.

Description : The use of _____ instruments is merely confined within laboratories as standardising instruments.

Last Answer : The use of absolute instruments is merely confined within laboratories as standardizing instruments.

Moving iron and PMMC instruments can be distinguished from each other by looking at:

Last Answer : Moving iron and PMMC instruments can be distinguished from each other by looking at: Scale

Commonly used instruments in power system measurement are?

Last Answer : Commonly used instruments in power system measurement are induction.

Operating torques in analogue instruments are?

Last Answer : Operating torques in analogue instruments are deflecting, control and damping.

The power factor of a single phase load can be calculated if the instruments available are?

Last Answer : The power factor of a single phase load can be calculated if the instruments available are three ammeters or three voltmeters.

The switch board instruments?

Last Answer : The switch board instruments should be mounted in vertical position.

According to application, instruments are classified as?

Last Answer : According to application, instruments are classified as switch board, portable.

Which instruments are those which measure the total quantity of electricity delivered in a particular time?

Last Answer : Integrating instruments are those which measure the total quantity of electricity delivered in a particular time.

The use of which instruments is merely confined within laboratories as standardizing instruments?

Last Answer : The use of absolute instruments is merely confined within laboratories as standardizing instruments.

What do you mean by secondary instruments?

Description : What do you mean by secondary instruments?

Last Answer : The instruments which will give the direct readings are called secondary instruments

where springs of low damping are required for the purpose of vibration isolation, it will be most desirable to use A) Metallic springs B) Rubber pad C) Air springs D) Neoprene pads

Description : where springs of low damping are required for the purpose of vibration isolation, it will be most desirable to use A) Metallic springs B) Rubber pad C) Air springs D) Neoprene pads

Last Answer : A) Metallic springs

Instruments used to measure air pressure are called?

Description : Instruments used to measure air pressure are called?

Last Answer : Barometer