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

$A$ galvanometer coil has a resistance $90\, \Omega$ and full-scale deflection current $10\, mA$. $A$ $910\, \Omega$ resistance is connected in series with the galvanometer to make a voltmeter. If the least count of the voltmeter is $0.1\, V$,the number of divisions on its scale is:

$A$ galvanometer of resistance $20 \Omega$ gives a deflection of $5$ divisions when $1 \text{ mA}$ current flows through it. The galvanometer scale has $50$ divisions. To convert the galvanometer into a voltmeter of range $25 \text{ V}$,we should connect a resistance of

$A$ galvanometer of $100\,\Omega$ resistance gives full-scale deflection when $10\,mA$ of current is passed. To convert it into a $10\,A$ range ammeter,the resistance of the shunt required will be ............... $\Omega$.

$A$ galvanometer acting as a voltmeter should have . . . . . . .

$A$ moving coil galvanometer is converted into an ammeter of range $0$ to $5 \, mA$. The galvanometer resistance is $90 \, \Omega$ and the shunt resistance has a value of $10 \, \Omega$. If there are $50$ divisions in the galvanometer-turned-ammeter on either side of zero, its current sensitivity is

Vedclass Test Series

Exam Paper Generator

Online Exam Module