Moving Coil Galvanometer, Ammeter & Voltmeter

If the number of turns in the coil of a moving coil galvanometer decreases, the resistance of the galvanometer,

An ammeter has resistance $R$ and range $I$. What resistance should be connected in parallel with it to increase its range by $nI$?

The value of shunt resistance that allows $5\%$ of the main current through the galvanometer of $100\ \Omega$ is nearly

The current passing through the galvanometer is 4 % of the total current in the curcuit. If the resistance of the galvanometer is 'G', the shunt resistance 'S' connected across the galvanometer is

If a galvanometer is shunted by $\left(\frac{1}{n-1}\right)^{th}$ of the value of its resistance, then the fraction of the total current passing through the galvanometer is

A galvanometer has resistance G and range Vg. How much resistance is required to read voltage up to V volt?

A rectangular coil of effective area $0.04$ m$^{2}$ is suspended freely in a radial magnetic field of $0.02$ Wb/m$^{2}$. The torsional constant of the suspension fibre is $5 \times 10^{-9}$ Nm/degree. If a current of $250\ \mu$A is passed through it, then the angle through which it rotates is

When current $I$ is passed through galvanometer coil, it is deflected through $16^\circ$. But when it is shunted by a resistance of $8\ \Omega$, the same current produces a deflection of $4^\circ$. The resistance of the galvanometer is

When a galvanometer is shunted by a resistance 'S', its current capacity increases 'n' times. If the same galvanometer is shunted by another resistance '$S'$', its current capacity will increase to '$n'$ '. The value of n in terms of $n'$, S and $S'$ is

A galvanometer has a current range of $10$ mA and a voltage range of $0.75$ V. To convert this galvanometer into an ammeter of range $10$ A, what is the shunt resistance?

A moving coil of galvanometer when shunted with $2\ \Omega$ resistance gives a full scale deflection for a current of 500 mA. When a resistance of $470\ \Omega$ is connected in series it gives a full scale deflection for 10 V potential applied on it. The value of resistance of galvanometer coil is $\rule{2em}{0.4pt}\ \Omega$.

A voltmeter with series resistance $R$ has a range $(0 - V_1)$ volt. With a series resistance of $4R$, its range becomes $(0 - V_2)$ volt. The relation between $V_1$ and $V_2$ is

A galvanometer of resistance $50\ \Omega$ is connected to a battery of $3$V along with a resistance of $2950\ \Omega$ in series. A full scale deflection of $30$ divisions is obtained in the galvanometer. To reduce this deflection to $20$ divisions, the resistance in series should be

When a resistance of $100\ \Omega$ is connected in series with galvanometer of resistance $R$, its range is $V$. To double its range, another additional resistance of $1000\ \Omega$ is connected in series. Find the value of $R$.

When a resistance of $200\ \Omega$ is connected in series with a galvanometer of resistance G, its range is V. To triple its range, a resistance of $2000\ \Omega$ is connected in series. The value of G is

In a moving coil galvanometer, two moving coils $\text{M}_1$ and $\text{M}_2$ have the following particulars: $\text{R}_1 = 5\Omega,\ \text{N}_1 = 15,\ \text{A}_1 = 3.6 \times 10^{-3}\text{ m}^{2},\ \text{B}_1 = 0.25\text{ T}$

$\text{R}_2 = 7\Omega,\ \text{N}_2 = 21,\ \text{A}_2 = 1.8 \times 10^{-3}\text{ m}^{2},\ \text{B}_2 = 0.50\text{ T}$

Assuming that torsional constant of the springs are same for both coils, what will be the ratio of voltage sensitivity of $M_1$ and $M_2$?

A moving coil galvanometer has 100 turns and each turn has an area of $2.0\text{ cm}^{2}$. The magnetic field produced by the magnet is $0.01\text{ T}$ and the deflection in the coil is 0.05 radian when a current of $10\text{ mA}$ is passed through it. The torsional constant of the suspension wire is $x \times 10^{-5}\text{ N-m/rad}$. The value of $x$ is _______.

For a moving coil galvanometer, the deflection in the coil is 0.05 rad when a current of 10 mA is passes through it. If the torsional constant of suspension wire is $4.0 \times 10^{-5}\text{ N m rad}^{-1}$, the magnetic field is 0.01T and the number of turns in the coil is 200, the area of each turn (in cm$^{2}$) is:

The current sensitivity of a galvanometer can be increased by:

(A) decreasing the number of turns

(B) increasing the magnetic field

(C) decreasing the area of the coil

(D) decreasing the torsional constant of the spring

Choose the most appropriate answer from the options given below:

A moving coil galvanometer has a coil with 175 turns and area 1 cm2. It uses a torsion band of torsion constant 10–6 N-m/rad. The coil is placed in a maganetic field B parallel to its plane. The coil deflects by 1° for a current of 1 mA. The value of B (in Tesla) is approximately :-

Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is

To know the resistance G of a galvanometer by half deflection method, a battery of emf VE and resistance R is used to deflect the galvanometer by angle $\theta$. If a shunt of resistance S is needed to get half deflection then G, R and S are related by the equation:

In an ammeter 0.2% of main current passes through the galvanometer. If resistance of galvanometer is G, the resistance of ammeter will be

A milli voltmeter of 25 milli volt range is to be converted into an ammeter of 25 ampare range. The value (in ohm) of neccessary shunt will be

A galvanometer of resistance, G, is shunted by a resistance S ohm. To keep the main current in the circuit unchanged, the resistance to be put in series with the galvanometer is

A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be

A galvanometer havings a coil resistance of 60 $\Omega$ shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents upto 5.0 amp by

A galvanometer of resistance 50 $\Omega$ is connected to a battery of 3 V along with a resistance of 2950 $\Omega$ in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be

The resistance of an ammeter is 13 $\Omega$ and its scale is graduated for a current upto 100 amps. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto 750 amperes by this meter. The value of shunt-resistance is

To convert a galvanometer into a voltmeter one should connect a

A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 $\times$ 10$-$4 ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of

To convert a galvanometer into a voltmeter one should connect a

To convert a galvanometer into a ammeter, one needs to connect a