Explain the principle ,working and construction of moving coil galvanometer.

Principle:

Its working is based on the fact that when a current carrying coil is placed in a magnetic field, it experiences a torque.

Working:

Suppose the coil PQRS is suspended freely in the magnetic field.

Let

l = Length PQ or RS of the coil

b = Breadth QR or SP of the coil

n = Number of turns in the coil

Area of each turn of the coil, A = l × b

Let B = Strength of the magnetic field in which coil is suspended

= Current passing through the coil in the direction PQRS

Let, at any instant, α be the angle which the normal drawn on the plane of the coil makes with the direction of magnetic field.

The rectangular coil carrying current when placed in the magnetic field experiences a torque whose magnitude is given by,

τ = nIBA sinα

Due to deflecting torque, the coil rotates and suspension wire gets twisted. A restoring torque is set up in the suspension wire.

Let θbe the twist produced in the phosphor bronze strip due to rotation of the coil and K be the restoring torque per unit twist of the phosphor bronze strip. Then,

Total restoring torque produced = kθ

In equilibrium position of the coil,

Deflecting torque = Restoring torque

∴ NIBA = kθ

Or, 

Where, [constant for a galvanometer]

It is known as galvanometer constant.

  • Current sensitivity of the galvanometer is the deflection per unit current. 

  • Voltage sensitivity is the deflection per unit voltage.

 

 

 

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 Conversion of a galvanometer to ammeter

  • A shunt (low resistance) is connected in parallel with the galvanometer.

Where,

I → Total current in circuit

G → Resistance of the galvanometer

Resistance of the shunt

I→ Current through galvanometer

Conversion of galvanometer to voltmeter

  • A high resistance is connected in series with the galvanometer.

Where,

→ Potential difference across the terminal A and B

Ig → Current through the galvanometer

R → High resistance

G → Resistance of galvanometer

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R=V/Ig-G

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 I = k * (alpha) / NAB

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This is the answer to explain the question.
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is galvanometer operate on self induction
    
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It is device to use the measure the electric current through a circuit Principle:- It is based on the fact that a current carring on coil Placed in a magnetic fields, it experience a torque Construction :- 1) consists a rectangular coil ABCD having n.no of turns. 2) the coil is placed b/w the magnetic field provide by permanent magnets n and s poles. 3)a cylindrical soft iron placed in b/w the coil to make the magnetic field residual. 4)the one of coil connected to terminal t1 and another end to a hair strip '. Working :- N= no. Of turns in coil A= area of coil B= magnitude of magnetic field I =current flowing on coil Then torque acting on coil Z=NIABcos
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Clear explaination of mcg
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The moving coil galvanometer consists of a coil, with many turns free to rotate about a fixed axis, in a uniform
radial magnetic field. The coil is wrapped on a cylindrical soft iron core which enables the field to remain radial
in all positions of the coil.
When a current flows through the coil, a torque acts on it.
  M B
 = NIAB sin
Here the symbols have their usual meaning. Since field is parallel to the plane of the coil at all positions
 = 90° ( is angle between area vector and magnetic field) and  = NIAB. The magnetic torque tends
to rotate the coil.
A spring Sp provides a counter torque K that balances the magnetic torque NIAB, resulting in a steady angular
deflection . In equilibrium
K = NIAB
where, K is torsional constant of the spring, that is restoring torque per unit twist. The deflection is indicated
on the scale by a pointer attached to the spring. We have
NAB
I
K
⎛ ⎞  ⎜ ⎟
⎝ ⎠
The quantity in brackets is a constant for a given galvanometer
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Shehnaaz sherin. Thank you for giving this much GU explanation 👍👌
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I mean gud explanation
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based on the principle that the current carring voil will experince max torque in a magnetic field
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Please give list of all  important diagram in class 12 physics.
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It is a device to measure the current in a circuit.
It's working principle is that,a current carrying rectangular loop placed in  a magnetic  field experiences a torque.
It consist of a coil of many turns free to rotate about an axis in a uniform radial magnetic field.
   
 
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principle ::when current carrying coil is placed in an uniform electric field it experiences a torque
construction ::
  • It consits of a rectangular coil of  fine insulated copper wire wounded on a light Al frame
  • A motion of  coil is controlled by the pair of heir springs of phosphorous and bronze
  • The springs experiences a restoring torque and can serve as current leads
  • A light Al pointer is attached to the coil to measure its deflection on a suitable scale
  •  A symmentrical coil is placed between the concave poles of  horshoe permanent magnets
  • There is a symmentrical soft iron core which not only makes the coil radial but also increases the magnetic strength
WORKING:::
        when coil is placed in a magnetic field it experiences a torque
so,
   T=F*perpendicular distance
   T=NIBb*sin90
​   T=NIB(ab)
   T=NIBA


HOPE IT HELPFUL FRNDS!!!


​ALL THE VERY BEST FRNDS
 
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yes, it is very useful bcoz it was asked in our intermediate exams
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TO Measure very low current
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Someone please explain!
Even mine is not answered!
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A GALVANOMETER IS A DEVICE THAT MEASURES THE MAGNITUDE AND DIRECTION OF CURRENT IN A CIRCUIT .
  IN A GALVANOMETER , THERE IS A NEEDLE ATTACHED TO A COIL, WHICH IS SUBJECT TO A MAGNETIC FIELD.ATTACHED TO THE COIL IS A SPRING SIMILAR TO THE HAIRSPRING ON THE BALANCE WHEEL OF A WATCH.
IN EQUILIBRIUM POSITION WITH NO CURRENT IN THE COIL, THE NEEDLE IS AT ZERO. WHEN THERE IS CURRENT IN THE COIL, MAGNETIC FIELD EXERTS A TORQUE ON IT , WHICH IS PROPORTIONAL TO THE CURRENT. THIS TORQUE IS RESPONSIBLE FOR THE ROTATION OF THE COIL AND HENCE THE NEEDLE DEFLECTS. AS HE COIL TURNS , THE SPRING EXERTS A RESONATING TORQUE THAT IS PROPORTIONAL TO THE ANGULAR DISPLACEMENT.
IT CONSISTS OF A SCALE, SPRING,POINTER,SOFT IRON CORE,MAGNETIC FIELD,PIVOTED COIL AND A PERMANENT MAGNET.
 
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What is the rate at which an object moves?????
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When a current carrying conductor placed in a magnetic field, it experiences a mechanical force given by Fleming?s Left Hand Rule
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Working:

l = Length PQ or RS of the coil

Area of each turn of the coil, A = l × b

Let, at any instant, α be the angle which the normal drawn on the plane of the coil makes with the direction of magnetic field.

Due to deflecting torque, the coil rotates and suspension wire gets twisted. A restoring torque is set up in the suspension wire.

In equilibrium position of the coil,

Or, 

 

  • Current sensitivity of the galvanometer is the deflection per unit current. 

  • Voltage sensitivity is the deflection per unit voltage.

 

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Working:

l = Length PQ or RS of the coil

Area of each turn of the coil, A = l × b

Let, at any instant, α be the angle which the normal drawn on the plane of the coil makes with the direction of magnetic field.

Due to deflecting torque, the coil rotates and suspension wire gets twisted. A restoring torque is set up in the suspension wire.

In equilibrium position of the coil,

Or, 

 

  • Current sensitivity of the galvanometer is the deflection per unit current. 

  • Voltage sensitivity is the deflection per unit voltage.

 

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Working:

l = Length PQ or RS of the coil

Area of each turn of the coil, A = l × b

Let, at any instant, α be the angle which the normal drawn on the plane of the coil makes with the direction of magnetic field.

Due to deflecting torque, the coil rotates and suspension wire gets twisted. A restoring torque is set up in the suspension wire.

In equilibrium position of the coil,

Or, 

 

  • Current sensitivity of the galvanometer is the deflection per unit current. 

  • Voltage sensitivity is the deflection per unit voltage.

 

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The electric field due to point charge enclosed by a spherical Gaussian surface does not suffer any changes when it's radius is increased because the charge enclosed by the surface is same. Increasing or decreasing the radius will not affect because it does not depend on radius.
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Please people do not put any other irrelevant question here!!!:(
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Please find this answer

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State the dc motor
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Can we use nickel spatula to stir 1m znso4 sollution
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Galvanometer is device used to detect current in a circuit.

Principle: A current carrying coil placed in a magnetic field experiences a current dependent torque which tends to rotate the coil, and thus produces an angular deflection.

Construction: A Weston (pivoted-type)(used in laboratories) galvanometer consists of a rectangular coil of insulated copper wire wound on a light non magnetic metallic (Aluminium) frame. This frame has got an axle. Both the ends of this axle are pivoted by jeweled bearings. The motion of the coil is controlled by a pair of hair springs of phosphor- bronze on both the ends which provide the restoring torque for the coil. These springs also act as current leads. A light aluminium pointer is also attached to the coil which helps to measure the deflection of the coil on the measuring scale. The coil is symmetrically placed between two cylindrical horse shoe magnets or, pole pieces of a strong permanent horse-shoe magnet. A cylindrical soft iron-core is also mounted. Since it has been mounted symmetrically between the concave cylindrical poles, the magnetic lines of force are allowed to act along the radius of the iron core. Thus, we get a radial magnetic field. The soft iron core due to its high permeability, intensifies the magnetic field. This increases the sensitivity of the galvanometer.

Theory and working:
Let:
I = current through the coil
a,b = Sides of the coil where, b is the side facing the magnets
A = ab = Area of the rectangular coil
N = Number of turns in the coil

As the magnetic field is radial, at every instant of time, the plane of the coil would be parallel to the magnetic field. The side a will also remain parallel to the magnetic field. Thus, the side a will not experience any force by the magnetic field. However, the side “b” of the coil would remain perpendicular to the magnetic field and thus experience a force. From Fleming’s left hand rule, we see that the two opposite “b” sides of the rectangular coil would experience equal and opposite force. This will constitute a couple and this will produce a torque.
This torque,
t = Force x perpendicular distance between the lines of action of the two forces
= BIbN x a sin(theta) where theta is the angle between the area vector and the magnetic field which is 90 degrees

So, the torque = BIbN x a = BINA

This torque deflects the coil by an angle alpha. A restoring torque acts on the coil, by the hair springs such that, restoring torque = k.alpha

where k is the torsion constant of the spring

Now, in equilibrium position,
k.alpha = BINA
Thus, alpha is directly proportional to I.
Thus, alpha = (NBA/k).I
Or, I = (k/NBA).alpha
Or, I = G.alpha

G is a constant, called Galvanometer constant and is constant for a galvanometer.

Meanwhile, the current which produces a deflection of one scale division is termed as the Figure of Merit of the galvanometer.

Sensitivity of a galvanometer: A galvanometer is said to be sensitive if it shows a large scale deflection even when a small amount of current is passed through it, or a small amount of voltage is applied across it.

CURRENT SENSITIVITY: The amount of deflection shown by a galvanometer when a unit current is passed through it. I(s) = alpha/I

VOLTAGE SENSITIVITY: The amount of deflection shown by a galvanometer when a unit potential difference is applied across the ends of the galvanometer. V(s) = alpha/V =alpha/IR = I(s)/R

[where, alpha = (NBA/k).I ]

Thus the factors on which the sensitivity of a moving coil galvanometer depends on, are:
1. Number of turns of the coil, N
2. Strength of magnetic field, B
3. Area of the rectangular coil, A
4. Torsion constant of the spring and the suspension wires, k

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yes
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Cyclotron
 Cyclotron is a device used to accelerate charged particles to high energies. It was devised by Lawrence.
Principle
Cyclotron works on the principle that a charged particle moving normal to a magnetic field experiences magnetic lorentz force due to which the particle moves in a circular path.
 Construction
It consists of a hollow metal cylinder divided into two sections D1 and D2 called Dees, enclosed in an evacuated chamber (Fig 3.21). The Dees are kept separated and a source of ions is placed at the centre in the gap between the Dees. They are placed between the pole pieces of a strong electromagnet. The magnetic field acts perpendicular to the plane of the Dees. The Dees are connected to a high frequency oscillator.
 
 
Working:
When a positive ion of charge q and mass m is emitted from the source, it is accelerated towards the Dee having a negative potential at that instant of time. Due to the normal magnetic field, the ion experiences magnetic lorentz force and moves in a circular path. By the time the ion arrives at the gap between the Dees, the polarity of the Dees gets reversed. Hence the particle is once again accelerated and moves into the other Dee with a greater velocity along a circle of greater radius. Thus the particle moves in a spiral path of increasing radius and when it comes near the edge, it is taken out with the help of a deflector plate (D.P). The particle with high energy is now allowed to hit the target T.
  
When the particle moves along a circle of radius r with a velocity v, the magnetic Lorentz force provides the necessary centripetal force.
 
Bqv = (vm2 ) / r
 v /r = Bq / m = constant ...(1)
 The time taken to describe a semi-circle
t = π r / v               (2)
 Substituting equation (1) in (2),
 t = π m/ Bq                   .. (3)
 It is clear from equation (3) that the time taken by the ion to describe a semi-circle is independent of
 (i) the radius (r) of the path and (ii) the velocity (v) of the particle
Hence, period of rotation T = 2t 
 T = 2 π m / Bq = constant ...(4)
 So, in a uniform magnetic field, the ion traverses all the circles in exactly the same time. The frequency of rotation of the particle,
v = 1 /T = Bq / 2 πm       .. (5)
If the high frequency oscillator is adjusted to produce oscillations of frequency as given in equation (5), resonance occurs.Cyclotron is used to accelerate protons, deutrons and α - particles.
  
 
 
Limitations
 a.     Maintaining a uniform magnetic field over a large area of the Dees is difficult.
 b.     At high velocities, relativistic variation of mass of the particle upsets the resonance condition.
 c.      At high frequencies, relativistic variation of mass of the electron is appreciable and hence electrons cannot be accelerated by cyclotron.
 
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Please do refer Xamidea of VK productions Such answers are very well written I that book Hope you'll find it useful☺
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SEE IN NCERT CLASS 12 BOOK
FOR A CLEAR EXP
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above answers is correct 
and helpful also
 
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Current carrying coil in a uniformmagnetic field it will experience a torque
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principle when a coil is placed in magnetic field it feel a torque
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Please find this answer

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Principle: it works on the principle that a current carrying coil placed in a uniform magnetic field experiences torque. Due to this torque the coil rotates. The coil rotates until it is balanced by opposing torque produced on springs or on the suspending wire.
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It is also by magnetic effect of current.

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A capacitor of unknown capacity is connected to a batttery of v volts . the charges stored in i8t is 360 uc . when potential v and the capacitor is reduved  by 120 volts, the charge stored in it becomes 120uc . calulate the potential v and the unknown capacityc. what will be the charge stored in the capacitor ,if the voltage applied had increased by 120 volts.

 
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Please find this answer

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the abhove ans are sufficient
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Hi f gn h
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Is a device which is used to detect the current flowing through a conductor.a galvanometer Weston type is viewed from top.magnetic field lines are produced by the concave poles.as it rotates torque is produced balanced by the counter torque produced by phosphorus bronze strings.
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Please find this answer

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1st part

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2nd part

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3rd part
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4th part

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Answer i am sent by image
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V is equal to IR
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Lenz law
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Galvanometer

Definition: The galvanometer is the device used for detecting the presence of small current and voltage or for measuring their magnitude. The galvanometer is mainly used in the bridges and potentiometer where they indicate the null deflection or zero current.

Principle of Galvanometer

The potentiometer is based on the premise that the current sustaining coil is kept between the magnetic field experiences a torque.

Construction of the Galvanometer

The construction of the potentiometer is shown in the figure below.

galvanometerThe moving coil, suspension, and permanent magnet are the main parts of the galvanometer.

Moving Coil – The moving coil is the current carrying part of the galvanometer. It is rectangular or circular and has the number of turns of fine copper wire. The coil is freely moved about its vertical axis of symmetry between the poles of a permanent magnet. The iron core provides the low reluctance flux path and hence provides the strong magnetic field for the coil to move in.

Suspension – The coil is suspended by a flat ribbon which carries the current to the coil. The other current carrying coil is the lower suspension whose torque effect is negligible. The upper suspension coil is made up of gold or copper wire which is made in the form of a ribbon. The mechanical strength of the wire is not very strong, and hence the galvanometers handle carefully without any jerks.

Mirror – The suspension carries a small mirror which casts the beam of light. The beam of light placed on the scale on which the deflection is measured.

Torsion Head – The torsion head is used for controlling the position of the coil and for adjusting the zero setting.

Applications of Galvanometer

The galvanometer has following applications. They are

  • It is used for detecting the direction of current flows in the circuit. It also determines the null point of the circuit. The null point means the situation in which no current flows through the circuit.
  • It is used for measuring the current.
  • The voltage between any two points of the circuit is also determined through galvanometer.

Working of Galvanometer

Let, l, d – the length of respective vertical and horizontal side of the coil in the meter.
N – number of turns in the coil,
B – Flux density in the air gap, wb/m2
i – current through moving coil in Ampere
K – spring constant of suspension, Nm/rad
θf – final steady-state deflection of moving coil in radiance
When the current flows through the coil, it experiences a torque which is expressed as

galvanometer-equation-1The force on each side of the coil is given as,
galvanometer-equation-2Hence deflecting torque becomes, galvanometer-equation-3galvanometer-4Where, galvanometer-equation-5N, B, A  are the constant of the galvanometer.

galvanometer-5The G is called the displacement constant of the galvanometer, and their value is equal NBA = NBld.

The controlling torque exerted by the suspension at deflection θF isgalvanometer-equation-8For final steady deflection, galvanometer-6Hence final steady deflection,

galvanometer-7For the small deflection angle, the deflection is expressed as the product of the radius and angle of the turned. By the reflected beam, it is expressed as 1000 Χ 2θF = 2000 Gi / K in millimetre.

The above equation shows that when the mirror turns through an angle θF the reflected beam turns through an angle 2θF shown in the figure below.

mirror-deflectionConversion of Galvanometer into an Ammeter

The galvanometer is used as an ammeter by connecting the low resistance wire in parallel with the galvanometer. The potential difference between the voltage and the shunt resistance are equal.

ammeter-as-a-galvanometer

galvanometer-equation-10

Where, S = shunt resistance and Is = current across the shunt.

As the galvanometer and the shunt resistance are connected in potential with the circuit, their potentials are equal.galvanometer-equation-11

Thus, the shunt resistance is given as, galvanometer-12

The value of the shunt current is very small as compared to the supply current.

Conversion of Galvanometer into a voltmeter

The galvanometer is used as a voltmeter by connecting the high resistance in series with the circuit.

voltmeter-as-a-galvanometer

galvanometer-equation-9

The range of the voltmeter depends on the value of the resistance connected in series with the circuit.

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A MOVING COIL GALVANOMETER IS ONE WHICH  DETECT THE PRESENCE OF ELECTRIC OR MAGNETIC FIELD INSIDE A CONDUCTOR
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ok
 
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When a current carrying coil is placed in a magnetic field then it experiences torque and deflect.
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the above answer is correct
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Please find this answer

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Principle and working : A current carrying coil placed in a uniform magnetic field, can experience a torque.

consider a rectangular coil for which no. or turns = N,

Area of cross-section = l x b = A,

Intensity of the uniform magnetic field = B,

Current through the coil = I

(k = restoring torque per unit twist)

The deflection of the coil is therefore, proportional to the current flowing through it.

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moving coilm galn=vanometer
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twsjqezig..kgxib
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If frequency is 12 the what will be the answer??
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Use navneet for this question
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Physics Wallah ??
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Ans is 2nd.

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Moving coil galvanometer is an?electromagnetic?device that can measure small values of current. It consists of?permanent horseshoe magnets, coil, soft iron core, pivoted spring, non-metallic frame, scale,?and pointer.

Principle

Torque?acts on a current carrying coil suspended in the uniform magnetic field. Due to this, the coil rotates. Hence, the deflection in the coil of a moving coil galvanometer is directly proportional to the current flowing in the coil.

?

[source: Redefining The Knowledge]

The Moving Coil Galvanometer

Construction

It consists of a rectangular coil of a large number of turns of thinly insulated copper wire wound over a light metallic frame. The coil is suspended between the pole pieces of a horseshoe magnet by a fine phosphor ? bronze strip from a movable torsion head. The lower end of the coil is connected to a hairspring of phosphor bronze having only a few turns.

The other end of the spring is connected to a binding screw. A soft iron cylinder is placed symmetrically inside the coil. The hemispherical magnetic poles produce a radial?magnetic field?in which the plane of the coil is parallel to the magnetic field in all its positions. A small plane mirror attached to the suspension wire is used along with a lamp and scale arrangement to measure the deflection of the coil.
  • 0
go and search NCERT
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  • 0
But the exact answer is 4/27?10^-13(2j-k)
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