A galvanometer gives full scale deflection with $0.006$ A current. By connecting it to a $4990 \ \Omega$ resistance, it can be converted into a voltmeter of range $0-30 \ V$. If connected to a $\frac{2 n }{249} \Omega$ resistance, it becomes an ammeter of range $0-1.5 \ A$. The value of $n$ is:
IIT 2014, Diffcult
Download our app for free and get started
$\frac{6}{1000}(G+4990)=30 $
$\Rightarrow G+4990=\frac{30,000}{6}=5000 $
$\Rightarrow G=10 $
$\frac{6}{1000} \times 10=\left(1.5-\frac{6}{1000}\right) S $
$\Rightarrow S =\frac{60}{1494}=\frac{2 n}{249} $
$\Rightarrow=\frac{249 \times 30}{1494}=\frac{2490}{498}=5$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1A long copper tube of inner radius $R$ carries a current $i$. The magnetic field $B$ inside the tube isView Solution
- 2In the hydrogen atom, the electron is making $6.6 \times {10^{15}}\,r.p.s.$ If the radius of the orbit is $0.53 \times {10^{ - 10}}\,metre,$ then magnetic field produced at the centre of the orbit is......$Tesla$View Solution
- 3A circular loop has a radius of $5\, cm$ and it is carrying a current of $0.1\, amp$. Its magnetic moment isView Solution
- 4View SolutionElectrons moving with different speeds enter a uniform magnetic field in a direction perpendicular to the field. They will move along circular paths.
- 5A square loop of side $l$ is kept in a uniform magnetic field $B$ such that its plane makes an angle $\alpha$ with $\vec{B}$. The loop carries a current $i$. The torque experienced by the loop in this position isView Solution
- 6$AB$ and $CD$ are smooth parallel rails, separated by a distance $l$, and inclined to the horizontal at an angle $\theta$ . $A$ uniform magnetic field of magnitude $B$, directed vertically upwards, exists in the region. $EF$ is a conductor of mass $m$, carrying a current $i$. For $EF$ to be in equilibrium,View Solution
- 7A particle of mass $m = 1.67 \times 10^{-27}\, kg$ and charge $q = 1.6 \times 10^{-19} \, C$ enters a region of uniform magnetic field of strength $1$ $tesla$ along the direction shown in the figure. If the direction of the magnetic field is along the outward normal to the plane of the paper, then the time spent by the particle in the region of the magnetic field after entering it at $C$ is nearly :-......$ns$View Solution
- 8A circular coil ‘$A$’ has a radius $R$ and the current flowing through it is $I$. Another circular coil ‘$B$’ has a radius $2R$ and if $2I$ is the current flowing through it, then the magnetic fields at the centre of the circular coil are in the ratio of (i.e.${B_A}$ to ${B_B}$)View Solution
- 9View SolutionTwo free parallel wires carrying currents in opposite direction
- 10In a moving coil galvanometer, the deflection of the coil $\theta $ is related to the electrical current $i$ by the relationView Solution