Suppose an isolated north pole is kept at the centre of a circular loop carrying a electric current $i$. The magnetic field due to the north pole at a point on the periphery of the wire is $B$. The radius of the loop is $a$. The force on the wire is
  • ANearly $2 \pi a i B$ perpendicular to the plane of the wire
  • B$2 \pi a i B$ in the plane of the wire
  • C$\pi a i B$ along the axis of the wire
  • D$0$
Medium
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
    If a current is passed through a spring then the spring will
    View Solution
  • 2
    A charge $q$ is moving in a magnetic field then the magnetic force does not depend upon
    View Solution
  • 3
    An electron is moving with a speed of ${10^8}\,m/\sec $ perpendicular to a uniform magnetic field of intensity $B$. Suddenly intensity of the magnetic field is reduced to $B/2$. The radius of the path becomes from the original value of $r$
    View Solution
  • 4
    A proton enters a magnetic field of flux density $1.5\,weber/{m^2}$ with a velocity of $2 \times {10^7}\,m/\sec $ at an angle of $30^\circ $ with the field. The force on the proton will be
    View Solution
  • 5
    An electron moves with speed $2 \times {10^5}\,m/s$ along the positive $x$-direction in the presence of a magnetic induction $B = \hat i + 4\hat j - 3\hat k$ (in $Tesla$) The magnitude of the force experienced by the electron in Newton's is (charge on the electron =$1.6 \times {10^{ - 19}}C)$
    View Solution
  • 6
    The current in the windings of a toroid is $2.0\,A$. There are $400\,turns$ and the mean circumferential length is $40\,cm$. If the inside magnetic field is $1.0\,T,$ the relative permeability is near to
    View Solution
  • 7
    A long solenoid has $n$ turns per meter and current $I\, A$ is flowing through it. The magnetic field at the ends of the solenoid is
    View Solution
  • 8
    A straight wire carrying a current of $14\,A$ is bent into a semicircular are of radius $2.2\,cm$ as shown in the figure. The magnetic field produced by the current at the centre $(O)$ of the arc. is $.........\,\times 10^{-4}\, T$
    View Solution
  • 9
    A proton moving with a velocity, $2.5 \times {10^7}\,m/s$, enters a magnetic field of intensity $2.5\,T$ making an angle ${30^o}$ with the magnetic field. The force on the proton is
    View Solution
  • 10
    A thin ring of $10\, cm$ radius carries a uniformly distributed charge. The ring rotates at a constant angular speed of $40\,\pi \,rad\,{s^{ - 1}}$ about its axis, perpendicular to its plane. If the magnetic field at its centre is $3.8 \times {10^{ - 9}}\,T$, then the charge carried by the ring is close to $\left( {{\mu _0} = 4\pi  \times {{10}^{ - 7}}\,N/{A^2}} \right)$
    View Solution