An electron is the ground state of hydrogen atom is revolving in anticlockwise direction in a circular orbit of radius $'r'$. The atom is placed is a unifom magnetic field $B$ in such a way magnetic moment of orbital electron makes an angle $30^o$ with the magnetic field. The torque experienced by orbital electon is
  • A$\frac {ehB}{4\pi m}$
  • B$\frac {ehB}{8\pi m}$
  • C$\frac {ehB}{2\pi m}$
  • D$\frac {\sqrt 3 ehB}{8\pi m}$
Diffcult
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
    Figure shows a square current carrying loop $ABCD$ of side $10\,\, cm$ and current $i = 10\,A$. The magnetic moment $\vec M$ of the loop is
    View Solution
  • 2
    The magnetic field at the center of current carrying circular loop is $B _{1}$. The magnetic field at a distance of $\sqrt{3}$ times radius of the given circular loop from the center on its axis is $B_{2}$. The value of $B_{1} / B_{2}$ will be.
    View Solution
  • 3
    A very long wire $ABDMNDC$ is shown in figure carrying current $I. AB$ and $BC$ parts are straight, long and at right angle. At $D$ wire forms a circular turn $DMND$ of radius $R. AB.$ $\mathrm{BC}$ parts are tangential to circular turn at $\mathrm{N}$ and $D$. Magnetic field at the centre of circle is
    View Solution
  • 4
    A magnet of magnetic moment $ 20 $ $C.G.S.$  units is freely suspended in a uniform magnetic field of intensity $0.3 $ $ C.G.S.$ units. The amount of work done in deflecting it by an angle of $30°$ in $ C.G.S.$  units is
    View Solution
  • 5
    Two concentric circular loops of radii $r _{1}=30\,cm$ and $r_{2}=50\,cm$ are placed in $X - Y$ plane as shown in the figure. $A$ current $I=7\,A$ is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately.
    View Solution
  • 6
    Assertion : If the current in a solenoid is reversed in direction while keeping the same magnitude, the magnetic field energy stored in the solenoid decreases.

    Reason : Magnetic field energy density is proportional to square of current.

    View Solution
  • 7
    A vertical straight conductor carries a current vertically upwards. A point $P$ lies to the east of it at a small distance and another point $Q$ lies to the west at the same distance. The magnetic field at $P$ is
    View Solution
  • 8
    $A, B$ and $C$ are parallel conductors of equal length carrying currents $I, I$ and $2I$ respectively. Distance between $A$ and $B$ is $x$. Distance between $B$ and $C$ is also $x$. ${F_1}$ is the force exerted by $B$ on $A$ and $F_2$ is the force exerted by $B$ on $A$ choose the correct answer
    View Solution
  • 9
    The resistance of an ideal ammeter is
    View Solution
  • 10
    Assertion : The magnetic field at the centre of the circular coil in the following figure due to the currents $I_1$ and $I_2$ is zero.

    Reason : $I_1 = I_2$ implies that the fields due to the current $I_1$ and $I_2$ will be balanced.

    View Solution