The number of turns in a coil of a galvanomet | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) The current sensitivity $(I_s)$ of a galvanometer is given by $I_s = \frac{	heta}{I} = \frac{NAB}{k}$,where $N$ is the number of turns,$A$ is the

Vedclass · Accepted Answer

Voltage sensitivity remains constant and current sensitivity increases $3$ times.

Vedclass · Answer

(D) The current sensitivity $(I_s)$ of a galvanometer is given by $I_s = \frac{	heta}{I} = \frac{NAB}{k}$,where $N$ is the number of turns,$A$ is the area,$B$ is the magnetic field,and $k$ is the restoring torque constant per unit twist.If $N$ is tripled $(N' = 3N)$,then $I_s' = \frac{(3N)AB}{k} = 3 I_s$. Thus,current sensitivity increases $3$ times.The voltage sensitivity $(V_s)$ is given by $V_s = \frac{	heta}{V} = \frac{	heta}{IR} = \frac{I_s}{R}$.Since the resistance $R$ is proportional to the length of the wire,and the length of the wire is proportional to the number of turns $(R' = 3R)$,the new voltage sensitivity is $V_s' = \frac{3I_s}{3R} = \frac{I_s}{R} = V_s$.Therefore,voltage sensitivity remains constant and current sensitivity increases $3$ times.

The number of turns in a coil of a galvanometer is tripled. Then:

Similar Questions

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

$A$ circuit contains an ammeter,a battery of $30\,V$ and a resistance of $40.8\,\Omega$ all connected in series. If the ammeter has a coil of resistance $480\,\Omega$ and a shunt of $20\,\Omega$,the reading in the ammeter will be .................. $A$.

$A$ galvanometer coil has a resistance of $990 \,\Omega$. It shows a full-scale deflection for a current of $10 \,mA$. Calculate the value of the shunt resistance required to convert it into an ammeter of range $1 \,A$.

$A$ galvanometer may be converted into an ammeter or a voltmeter. In which of the following cases will the resistance of the device so obtained be the largest?

The value of the shunt resistance that allows $10 \%$ of the main current through the galvanometer of $99 \Omega$ is (in $\Omega$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module