A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for (1/3) deflection in the galvanometer. Which of the below is true for measuring value of G ?

Question

A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for (1/3) deflection in the galvanometer. Which of the below is true for measuring value of G ? (A) (1/3) deflection method cannot be used for determining the resistance of the galvanometer. (B) (1/3) deflection method can be used and in this case the G equals to twice the value of shunt resistance(s). (C) (1/3) deflection method can be used and in this case, the G equals to three times the value of shunt resistance(s) (D) (1/3) deflection method can be used and in this case the G value equals to the shunt resistance(s).

Tardigrade Admin · Accepted Answer

In galvanometer ⇒( I - I g ) S = I g G <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/479df0698ec0fd2be5ff2b6239d930fd-.png" /> (Ig/I)=(S/S+G) ⇒ (1/3)=(S/S+G) ⇒ S+G=3 S ⇒ G=2 S

Q. A teacher in his physics laboratory allotted an experiment to determine the resistance $(G)$ of a galvanometer. Students took the observations for $\frac{1}{3}$ deflection in the galvanometer. Which of the below is true for measuring value of $G$ ?

$\frac{1}{3}$ deflection method cannot be used for determining the resistance of the galvanometer.

$\frac{1}{3}$ deflection method can be used and in this case the $G$ equals to twice the value of shunt resistance(s).

$\frac{1}{3}$ deflection method can be used and in this case, the $G$ equals to three times the value of shunt resistance(s)

$\frac{1}{3}$ deflection method can be used and in this case the $G$ value equals to the shunt resistance(s).

In galvanometer
$\Rightarrow (I - I_{g}) S = I_{g} G$

$\frac{I _{g}}{I} = \frac{S}{S + G}$
$\Rightarrow \frac{1}{3} = \frac{S}{S + G}$
$\Rightarrow S + G = 3 S$
$\Rightarrow G = 2 S$

Q. A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for 31​ deflection in the galvanometer. Which of the below is true for measuring value of G ?

31​ deflection method cannot be used for determining the resistance of the galvanometer.

31​ deflection method can be used and in this case the G equals to twice the value of shunt resistance(s).

31​ deflection method can be used and in this case, the G equals to three times the value of shunt resistance(s)

31​ deflection method can be used and in this case the G value equals to the shunt resistance(s).