A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 Ω resistance, it can be converted into a voltmeter of range 0-30 V. If connected to a (2 n /249) Ω resistance, it becomes an ammeter of range 0-1.5 A. The value of n is

Question

A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 Ω resistance, it can be converted into a voltmeter of range 0-30 V. If connected to a (2 n /249) Ω resistance, it becomes an ammeter of range 0-1.5 A. The value of n is (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/33465ff85ef097cd094cb96959f12605-.png" /> i =( V / R ) 0.006=(30/4990+ R ) R =10 i RG =0.006 i RS =1.494 Since RG and RS are in parallel, iG RG=iS RS 0.006 R =1.494((2 n /249)) ∴ n =5

Q. A galvanometer gives full scale deflection with $0.006 A$ current. By connecting it to a $4990 Ω$ resistance, it can be converted into a voltmeter of range $0 - 30 V$ . If connected to a $\frac{2 n}{249} Ω$ resistance, it becomes an ammeter of range $0 - 1.5 A$ . The value of $n$ is

$i = \frac{V}{R}$
$0.006 = \frac{30}{4990 + R}$
$R = 10$
$i_{RG} = 0.006$
$i_{RS} = 1.494$
Since $R_{G}$ and $R_{S}$ are in parallel,
$i_{G} R_{G} = i_{S} R_{S}$
$0.006 R = 1.494 (\frac{2 n}{249})$
$∴ n = 5$

Q. A galvanometer gives full scale deflection with 0.006A current. By connecting it to a 4990Ω resistance, it can be converted into a voltmeter of range 0−30V. If connected to a 2492n​Ω resistance, it becomes an ammeter of range 0−1.5A. The value of n is

i=RV​ 0.006=4990+R30​ R=10 iRG​=0.006 iRS​=1.494 Since RG​ and RS​ are in parallel, iG​RG​=iS​RS​ 0.006R=1.494(2492n​) ∴n=5

Q. A galvanometer gives full scale deflection with $0.006 A$ current. By connecting it to a $4990 Ω$ resistance, it can be converted into a voltmeter of range $0 - 30 V$ . If connected to a $\frac{2 n}{249} Ω$ resistance, it becomes an ammeter of range $0 - 1.5 A$ . The value of $n$ is

$i = \frac{V}{R}$
$0.006 = \frac{30}{4990 + R}$
$R = 10$
$i_{RG} = 0.006$
$i_{RS} = 1.494$
Since $R_{G}$ and $R_{S}$ are in parallel,
$i_{G} R_{G} = i_{S} R_{S}$
$0.006 R = 1.494 (\frac{2 n}{249})$
$∴ n = 5$