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प्रश्न
The fraction of the total current passing through the galvanometer is ............ .
a) `S/(S+G)`
b) `G/(S+G)`
c) `(S+G)/G`
d) `(S+G)/S`
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उत्तर
a) `S/(S+G)`
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संबंधित प्रश्न
The combined resistance of a galvanometer of resistance 500Ω and its shunt is 21Ω. Calculate the value of shunt.
A rectangular coil of a moving coil galvanometer contains 50 turns each having area 12 cm2 . It is suspended in radial magnetic field 0.025 Wb/m2 by a fibre of twist constant 15 x10-10 Nm/degree. Calculate the sensitivity of the moving coil galvanometer.
Show that the current flowing through a moving coil galvanometer is directly proportional to the angle of deflection of coil.
Obtain the expression for current sensitivity of moving coil galvanometer.
Increasing the current sensitivity of a galvanometer may not necessarily increase its voltage sensitivity. Explain, giving reason.
Two moving coil meters, M1 and M2 have the following particulars:
R1 = 10 Ω, N1 = 30,
A1 = 3.6 × 10–3 m2, B1 = 0.25 T
R2 = 14 Ω, N2 = 42,
A2 = 1.8 × 10–3 m2, B2 = 0.50 T
(The spring constants are identical for the two meters.)
Determine the ratio of
- current sensitivity and
- voltage sensitivity of M2 and M1.
Explain how moving coil galvanometer is converted into a voltmeter. Derive the necessary formula.
A rectangular coil of a moving coil galvanometer contains 100 turns, each having area
15 cm2. It is suspended in the radial magnetic field 0.03 T. The twist constant of suspension
fibre is 15 x 10-10 N-m/degree. Calculate the sensitivity of the moving coil galvanometer.
A moving coil galvanometer has a resistance of 25Ω and gives a full scale deflection for a current of 10mA. How will you convert it into a voltmeter having range 0 - 100 V?
A galvanometer has a resistance of 16Ω. It shows full scale deflection, when a current of 20 mA is passed through it. The only shunt resistance available is 0.06 which is not appropriate to convert a galvanometer into an ammeter. How much resistance should be connected in series with the coil of galvanometer, so that the range of ammeter is 8 A?
Why is it necessary to introduce a radial magnetic field inside the coil of a galvanometer?
Can a galvanometer as such be used for measuring the current? Explain.
How will you convert a moving coil galvanometer into a voltmeter?
With the help of a neat and labelled diagram, explain the principle and working of a moving coil galvanometer ?
Define current sensitivity of a galvanometer.
Figure shows two circuits each having a galvanometer and a battery of 3V.
When the galvanometers in each arrangement do not show any deflection, obtain the ratio R1/R2.
Explain, giving reasons, the basic difference in converting a galvanometer into (i) a voltmeter and (ii) an ammeter?
State the principle of the working of a moving coil galvanometer, giving its labeled diagram ?
Outline the necessary steps to convert a galvanometer of resistance RG into an ammeter of a given range ?
State the underlying principle of working of a moving coil galvanometer. Write two reasons why a galvanometer can not be used as such to measure current in a given circuit. Name any two factors on which the current sensitivity of a galvanometer depends.
What are the advantages of using soft iron as a core, instead of steel, in the coils of galvanometers?
A coil of radius 10 cm and resistance 40 Ω has 1000 turns. It is placed with its plane vertical and its axis parallel to the magnetic meridian. The coil is connected to a galvanometer and is rotated about the vertical diameter through an angle of 180°. Find the charge which flows through the galvanometer if the horizontal component of the earth's magnetic field is BH = 3.0 × 10−5 T.
Why are the pole pieces of a horseshoe magnet in a moving coil galvanometer made cylinder in shape?
Explain the significance of a radial magnetic field when a current-carrying coil is kept in it.
A galvanometer coil has a resistance of 12 Ω and the metre shows full scale deflection for a current of 3 mA. How will you convert the metre into a voltmeter of range 0 to 18 V?
The deflection in a moving coil galvanometer is ______.
The current sensitivity of a galvanometer is defined as ______.
A moving coil galvanometer can be converted into an ammeter by ______.
The conversion of a moving coil galvanometer into a voltmeter is done by ______.
The current sensitivity of a galvanometer increase by 20%. If its resistance also increases by 25%, the voltage sensitivity will ______.
Assertion (A): On Increasing the current sensitivity of a galvanometer by increasing the number of turns may not necessarily increase its voltage sensitivity.
Reason (R): The resistance of the coil of the galvanometer increases on increasing the number of turns.
Select the most appropriate answer from the options given below:
A galvanometer of resistance 100 Ω gives a full-scale deflection for a current of 10−5 A. To convert it into an ammeter capable of measuring up to 1 A we should connect a resistance of ______.
A galvanometer having a coil resistance of 60 Ω shows full-scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents up to 5.0 amp by:
The coil of galvanometer consists of 100 turns and effective area of 1 square cm. The restoring couple is 10-8 N-m/rad. The magnetic field between the pole pieces is 5T. The current sensitivity of this galvanometer will be ______.
A multirange voltmeter can be constructed by using a galvanometer circuit as shown in figure. We want to construct a voltmeter that can measure 2V, 20V and 200V using a galvanometer of resistance 10Ω and that produces maximum deflection for current of 1 mA. Find R1, R2 and R3 that have to be used.
When a galvanometer is shunted with a 4 Ω resistance, the deflection is reduced to one-fifth. If the galvanometer is further shunted with a 2 Ω wire. The further reduction (find the ratio of decrease in current to the previous current) in the deflection will be (the main current remains the same)
A galvanometer having a resistance of 20 Ω and 30 Ω division on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is ______.
A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10-divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be ______.
Explain in brief the basic construction of a moving-coil table galvanometer whit a neat labelled diagram.
A voltmeter has a range of 0 - 20 V and a resistance of 500 Q. Explain how can be used to measure voltages from 0 - 200 volt?
A moving coil galvanometer of resistance 55 Ω produces a full scale deflection for a current of 250 mA. How will you convert it into an ammeter with a range of 0 - 3A?
To convert a moving coil galvanometer into an ammeter we need to connect a ______.
Assertion: When an electric current is passed through a moving coil galvanometer, its coil gets deflected.
Reason: A circular coil produces a uniform magnetic field around itself when an electric current is passed through it.
The figure below shows a circuit containing an ammeter A, a galvanometer G and a plug key K. When the key is closed:
A galvanometer of resistance 100 Ω gives a full-scale deflection for a potential difference of 200 mV.
- What must be the resistance connected to convert the galvanometer into an ammeter of the range 0-200 mA?
- Determine resistance of the ammeter.
