Class 12PhysicsMoving Charges and MagnetismThe Moving Coil Galvanometer (Sensitivity) and Ammeter and Voltmeter Conversion
MediumExplain the equation of a shunt.
(N/A) shunt is a low-resistance wire connected in parallel with a galvanometer to convert it into an ammeter.
Let $G$ be the resistance of the galvanometer and $I_g$ be the current for full-scale deflection.
Let $I$ be the total current to be measured and $S$ be the resistance of the shunt.
Since the shunt is in parallel with the galvanometer,the potential difference across both is the same:
$V_g = V_s$
$I_g G = (I - I_g) S$
Rearranging for the shunt resistance $S$:
$S = \frac{I_g G}{I - I_g}$
This equation allows us to calculate the required shunt resistance to extend the range of a galvanometer to a desired current $I$.
Let $G$ be the resistance of the galvanometer and $I_g$ be the current for full-scale deflection.
Let $I$ be the total current to be measured and $S$ be the resistance of the shunt.
Since the shunt is in parallel with the galvanometer,the potential difference across both is the same:
$V_g = V_s$
$I_g G = (I - I_g) S$
Rearranging for the shunt resistance $S$:
$S = \frac{I_g G}{I - I_g}$
This equation allows us to calculate the required shunt resistance to extend the range of a galvanometer to a desired current $I$.
Explore More
Similar Questions
Consider a moving coil galvanometer $(MCG)$ :
$A :$ The torsional constant in a moving coil galvanometer has dimensions $[ML^2 T^{-2}]$.
$B :$ Increasing the current sensitivity may not necessarily increase the voltage sensitivity.
$C :$ If we increase the number of turns $(N)$ to its double $(2N)$,then the voltage sensitivity doubles.
$D :$ $MCG$ can be converted into an ammeter by introducing a shunt resistance of a large value in parallel with the galvanometer.
$E :$ Current sensitivity of $MCG$ depends inversely on the number of turns of the coil.
Choose the correct answer from the options given below:
$A :$ The torsional constant in a moving coil galvanometer has dimensions $[ML^2 T^{-2}]$.
$B :$ Increasing the current sensitivity may not necessarily increase the voltage sensitivity.
$C :$ If we increase the number of turns $(N)$ to its double $(2N)$,then the voltage sensitivity doubles.
$D :$ $MCG$ can be converted into an ammeter by introducing a shunt resistance of a large value in parallel with the galvanometer.
$E :$ Current sensitivity of $MCG$ depends inversely on the number of turns of the coil.
Choose the correct answer from the options given below:
$A$ galvanometer,having a resistance of $50 \Omega$,gives a full scale deflection for a current of $0.05 \text{ A}$. The length in metre of a resistance wire of area of cross-section $2.97 \times 10^{-2} \text{ cm}^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5 \text{ A}$ current is: (Specific resistance of the wire $= 5 \times 10^{-7} \Omega\text{-m}$)
DifficultTS EAMCET 2003
View Solution$A$ voltmeter has a resistance of $G \ \Omega$ and a range of $V \ \text{volt}$. The resistance required in series to convert it into a voltmeter of range $nV \ \text{volt}$ is . . . . . . .
Give the unit of shunt.
Easy
View Solution$A$ moving coil galvanometer of resistance $100 \,\Omega$ is used as an ammeter using a shunt resistance of $0.1 \,\Omega$. The maximum deflection current in the galvanometer is $100 \,\mu A$. Find the minimum current in the circuit so that the ammeter shows maximum deflection in $mA$.
MediumIIT 2005
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo