A horizontal metallic rod of mass $'m'$ and length $'l'$ is supported by two vertical identical springs of spring of spring constant $'K'$ each and natural length $l_0.$  A current $'i'$ is flowing in the rod in the direction shown. If the rod is in equilibrium then the length of each spring in this state is :-
Diffcult
Download our app for free and get startedPlay store
The force on the rod due to magnetic field and gravity is

$ilB - mg$ (upwards)

Hence the extension in the springs is $\frac{{ilB - mg}}{{2k}}$ (Note that effective spring constant is $2k$)

Therefore the length of the spring is $\ell_{0}+$ $\frac{{ilB - mg}}{{2k}}$

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
    The earth’s magnetic field at a given point is $0.5 \times {10^{ - 5}}\,Wb{\rm{ - }}{m^{ - 2}}$. This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius $5.0\,cm$. The current required to be flown in the loop is nearly......$A$
    View Solution
  • 2
    If the angular momentum of an electron is $\vec J$ then the magnitude of the magnetic moment will be
    View Solution
  • 3
    Two charged particles, having same kinetic energy, are allowed to pass through a uniform magnetic field perpendicular to the direction of motion. If the ratio of radii of their circular paths is $6: 5$ and their respective masses ratio is $9: 4$. Then, the ratio of their charges will be.
    View Solution
  • 4
    At a distance of $10\, cm $ from a long straight wire carrying current, the magnetic field is $0.04\, T$. At the distance of $40\, cm$, the magnetic field will be....$T$
    View Solution
  • 5
    Statement $-1$ : Path of the charge particle may be straight line in uniform magnetic field.
    Statement $-2$ : Path of the charge particle is decided by the angle between its velocity and the magnetic force working on it
    View Solution
  • 6
    A wire of length $L$ $metre$ carrying a current of $I$ $ampere$ is bent in the form of a circle. Its magnitude of magnetic moment will be
    View Solution
  • 7
    A particle is projected with a velocity ( $10\ m/s$ ) along $y-$ axis from point $(2, 3)$ . Magnetic field of $\left( {3\hat i + 4\hat j} \right)$ Tesla exist uniformly in the space. Its speed when particle passes through $y-$ axis for the third time is : (neglect gravity)
    View Solution
  • 8
    Two infinitely long wires each carrying current $I$ along the same direction are made into the geometry as shown in the figure below. The magnetic field at the point $P$ is
    View Solution
  • 9
    An ionized gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the $+x$ direction and a magnetic field along the $+z$ direction, then
    View Solution
  • 10
    Two parallel long wires carry currents $i_1$ and $i_2$ with ${i_1} > {i_2}$. When the currents are in the same direction, the magnetic field midway between the wires is $10\, \mu T$. When the direction of $i_2$ is reversed, it becomes $40 \,\mu T$. the ratio ${i_1}/{i_2}$ is
    View Solution