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Answer :

The deflection of hot-wire instrument depends on: RMS value of the alternating current

Related questions

Last Answer : The instrument having its deflection depends upon average value is:  Rectifier type

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 :  In a gravity controlled instrument, the deflection angle is proportional to sine inverse of measurand.

Description : Hot wire ammeter is used (a) only for dc circuit (b) only for ac circuit (c) both (a) and (b) (d) Either (a) or (b) 

Last Answer : Either  a  or   b.

Description : Which of the following instrument can be used for measuring speed of a submarine moving in deep sea? (A) Venturimeter (B) Orifice plate (C) Hot wire anemometer (D) Pitot tube

Last Answer : Answer: Option D

Description : The scale of a hot-wire instrument is a/an ___function

Last Answer : squared

Description : A 0-10 A ammeter has a guaranteed accuracy of 1% of full scale deflection, the limiting error while reading 2.5 A will be (a) 1% (b) 2% (c) 4% (d) None of these 

Last Answer : A

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

Description : In a galvanometer, the deflection becomes one half when the galvanometer is shunted by a 20 ohm resistor. The galvanometer resistance is 

Last Answer : In a galvanometer, the deflection becomes one half when the galvanometer is shunted by a 20 ohm resistor. The galvanometer resistance is 10 Ohm

Description : The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. This is to have full deflection when 100V is measured. What is the value of series resistor to be used?

Last Answer : The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. This is to have full deflection when 100V is measured. 99.99 K ohms is the value of series resistor to be used.

Description :  The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. If this meter is to have full deflection at 5A, what is the value of the shunt resistance to be used?

Last Answer :  The full-scale deflection current of an ammeter is 1 mA and its internal resistance is 100Ohm. If this meter is to have full deflection at 5A, 1/49.99 ohms is the value of the shunt resistance to be used.

Last Answer :  In a free running oscilloscope, the horizontal deflection system is driven by a Ramp waveform

Last Answer : If two meters X and Y requires 40mA and 50mA respectively, to give full scale deflection, then: X is more sensitive

Last Answer : A sensitive galvanometer produces large deflection for a small value of current.

Description : What Difference between null type and deflection type instrument?

Last Answer : Need answer

Description : Accurate measurement of deflection angles with a transit not properly adjusted may be made by (A) Setting the Vernier A at zero at back station and then plunging the telescope (B) Setting the ... back sights one with the telescope normal and the other with telescope inverted (D) None of these

Last Answer : (C) Taking two back sights one with the telescope normal and the other with telescope inverted

Description : An angle of deflection right, may be directly obtained by setting the instrument to read (A) Zero on back station (B) 180° on back station (C) 90° (D) 270° on back station

Last Answer : (A) Zero on back station

Description : As the deflection of the moving system increases, the controlling torque in an indicating instrument.

Last Answer : increases

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

Last Answer : 50mA

Description : Derive the relation for deflection torque in PMMC instrument. 

Last Answer : Ans: The length of coil be l meter and width of coil be d meter. Assume I is the current flowing in the ciol having N turns. Assume B as the flux density in the air gap then F=BIL ... a direct indication of the current in the coil. The pointer deflection can therefore be used to measure current.

Description : Draw the diagram of PMMC instrument and state the deflection torque equation

Last Answer : Equation Ʈ= B*A*I*N Where r= torque Newton. Meter B = flux density in the air gap. Wb/m2 A = effective coil area (m) N= number of turns of wire of the coil

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 : Which of the following factors limit the deflection of the pointer of a PMMC instrument of about 90o?  1. Its damping mechanism  2. Linearity of magnetic field in which the coil moves  3. Control spring arrangement  4. ... Only 1 and 3 (b) Only 2 and 4 (c) Only 2 and 3 (d) Only 1 and 4 

Last Answer : Which of the following factors limit the deflection of the pointer of a PMMC instrument of about 90o?  1. Its damping mechanism  2. Linearity of magnetic field in which the coil moves  3. Control spring arrangement  4. ... Only 1 and 3 (b) Only 2 and 4 (c) Only 2 and 3 (d) Only 1 and 4 

Description : In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across `60 cm` of the potentiometer wire. If the cell is

Last Answer : In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across `60 cm` of ... ` C. `1.2Omega` D. `1.5Omega`

Description : `AB` is a wire of uniform resistance. The galvanometer `G` shows no deflection when the length `AC = 20 cm` and `CB = 80 cm`. The resistance `R` is eq

Last Answer : `AB` is a wire of uniform resistance. The galvanometer `G` shows no deflection when the length `AC = 20 cm ... ` B. `8Omega` C. `20Omega` D. `40Omega`

Description : The spring index is, (A) Ratio of wire diameter to mean coil diameter (B) Force per unit cross-sectional area of spring (C) Ratio of mean coil diameter to wire diameter (D) Force required to produce unit deflection

Last Answer : (C) Ratio of mean coil diameter to wire diameter

Description : The stiffness of spring is, (A) Deflection per unit of axial force (B) Force per unit cross-sectional area of spring (C) Ratio of mean coil diameter to wire diameter (D) Force required to produce unit deflection

Last Answer : (D) Force required to produce unit deflection

Description : A closely coiled helical spring of radius R, contains n turns and is subjected to an axial load W. If  the radius of the coil wire is r and modulus of rigidity of the coil material is C, the deflection of the  coil is  (A) WR3n/Cr4 (B) 2WR3n/Cr4 (C) 3WR3n/Cr4 (D) 4WR3n/Cr

Last Answer : (D) 4WR3n/Cr

Description : Pick out the wrong statement. (A) The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S (B) For a helical spring, deflection is ... is less than the buckling load (D) Modulus of resilience is proportional to (stress at elastic limit)2

Last Answer : (C) Crushing load or columns is less than the buckling load

Description : The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the (A) Ability to absorb shock (B) Capacity to store energy (C) Ratio of the wire & coil diameters (D) Load to produce unit deflection

Last Answer : Option D

Description : Find total number coils in a spring having square and ground ends. Deflection in the spring is 6mm when load of 1100N is applied. Modulus of rigidity is 81370N/mm². Wire diameter and pitch circle diameter are 10mm and 50mm respectively. a) 7 b) 6 c) 5 d) 4

Last Answer : a) 7

Description : The close-coiled helical springs ‘A’ and ‘B’ are of same material, same coil diameter, same wire diameter and subjected to same load. If the number of turns of spring ‘A’ is half that of spring ‘B’, the ratio of deflection of spring ‘A’ to spring ‘B’ is (a)1/2 (b) 1 (c) 2 (d) 4

Last Answer : (a)1/2

Description : In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft. (a) small (b) medium (c) large (d) any of the above.

Last Answer : (c) large

Description : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are  A) Perpendicular B) Parallel C) Inclined at 60" D) Inclined at 30°

Last Answer : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are Parallel 

Description :  In the case of an instrument reading of 8.3 V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is   (A) 1.810% (B) 0.181% (C)12.45% (D) 0.0018%

Last Answer :  In the case of an instrument reading of 8.3 V with a 0 to 150 voltmeter having a guaranteed accuracy of 1% full scale reading, the percentage limiting error is 12.45%

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 : 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 : 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 : Electrostatic instrument uses the principle of the variation of Capacitance with the voltage.

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

Last Answer : The repeat accuracy of an instrument can be judged from its standard deviation of error.

Last Answer : If the instrument is to have a wide range, the instrument should have Logarithmic scale.

Last Answer : The error of an instrument is normally given as a percentage of full-scale value.

Last Answer : An instrument to be used for measurement and control should preferably have Linear output and fast response

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

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

Last Answer : The sensitivity of an instrument is ratio of the change in the magnitude of the output to the corresponding change in the magnitude of the input.

Description :  The percentage limiting error, in the case of an instrument reading of 8.3V with a 0 to 150V voltmeter having a guaranteed accuracy of 1% full-scale reading is

Last Answer :  The percentage limiting error, in the case of an instrument reading of 8.3V with a 0 to 150V voltmeter having a guaranteed accuracy of 1% full-scale reading is 18.10%.