Two circular coils $X$ and $Y$, having equal number of turns, carry equal currents in the same sense and subtend same solid angle at point $O$. If the smaller coil, $X$ is midway between $O$ and $Y$, then if we represent the magnetic induction due to bigger coil $Y$ at $O$ as $BY$ and that due to smaller coil $X$ at $O$ as $BX$ , then
Diffcult
Download our app for free and get startedPlay store
(c) Magnetic field at $O$ due to bigger coil $Y$, is
${B_Y} = \frac{{{\mu _0}}}{{4\pi }}.\frac{{2\pi i{{(2r)}^2}}}{{{{\{ {d^2} + {{(2r)}^2}\} }^{3/2}}}} = \frac{{{\mu _0}}}{{4\pi }}.\frac{{8\pi i{r^2}}}{{{{({d^2} + 4{r^2})}^{3/2}}}}$
Magnetic field at $O$ due to smaller coil $X$ is
${B_X} = \frac{{{\mu _0}}}{{4\pi }}.\frac{{2\pi i{r^2}}}{{{{\left\{ {{{\left( {\frac{d}{2}} \right)}^2} + {r^2}} \right\}}^{3/2}}}} = \frac{{{\mu _0}}}{{4\pi }}.\frac{{16\pi i{r^2}}}{{{{({d^2} + 4{r^2})}^{3/2}}}}$
$==>$ $\;\frac{{{B_Y}}}{{{B_X}}} = \frac{1}{2}$
art

Download our app
and 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

  • 1
    Find the magnitude of magnetic field at point $p$ due to a semi - infinite wire given below
    View Solution
  • 2
    A 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. The speed of the particle is $10^7\, m/s.$ The magnetic field is directed along the inward normal to the plane of the paper. The particle enters the field at $C$ and leaves at $D.$ Then the angle $\theta$ must be :-.........$^o$
    View Solution
  • 3
    A coil carrying electric current is placed in uniform magnetic field, then
    View Solution
  • 4
    A coil having $N$ $turns$ is wound tightly in the form of a spiral with inner and outer radii $a$ and $b$ respectively. When a current $I$ passes through the coil, the magnetic field at the centre is
    View Solution
  • 5
    If an ammeter is connected in parallel to a circuit, it is likely to be damaged due to excess
    View Solution
  • 6
    An electron moves straight inside a charged parallel plate capacitor of uniform charge density. The space between the plates is filled with uniform magnetic field of intensity $B ,$ as shown in the figure, Neglecting effect of gravity, the time of straight line motion of the electron in the capacitor is 
    View Solution
  • 7
    An ammeter gives full scale deflection when current of $1.0\, A$ is passed in it. To convert it into $10\, A$ range ammeter, the ratio of its resistance and the shunt resistance will be
    View Solution
  • 8
    The current is flowing in south direction along a power line. The direction of magnetic field above the power line (neglecting earth's field) is
    View Solution
  • 9
    A proton with a kinetic energy of $2.0\,eV$ moves into a region of uniform magnetic field of magnitude $\frac{\pi}{2} \times 10^{-3}\,T$. The angle between the direction of magnetic field and velocity of proton is $60^{\circ}$. The pitch of the helical path taken by the proton is $..........cm$ (Take, mass of proton $=1.6 \times 10^{-27}\,kg$ and Charge on proton $=1.6 \times 10^{-19}\,kg)$
    View Solution
  • 10
    The pole strength of a bar magnet is $48$  $ampere-metre$ and the distance between its poles is $ 25 \,cm$ . The moment of the couple by which it can be placed at an angle of $30°$ with the uniform magnetic intensity of flux density $0.15 $ $Newton /ampere-metre$ will be.......$Newton × metre$ 
    View Solution