Two long straight wires $P$ and $Q$ carrying equal current $10\,A$ each were kept parallel to each other at $5\,cm$ distance. Magnitude of magnetic force experienced by $10\,cm$ length of wire $P$ is $F_1$. If distance between wires is halved and currents on them are doubled, force $F_2$ on $10\,cm$ length of wire $P$ will be :
JEE MAIN 2023, Medium
Download our app for free and get startedPlay store
Force per unit length between two parallel straight

$\text { wires }=\frac{\mu_0 i_1 i_2}{2 \pi d }$

$\frac{ F _1}{ F _2}=\frac{\frac{\mu_0(10)^2}{2 \pi(5\,cm )}}{\frac{\mu_0(20)^2}{2 \pi\left(\frac{5 cm }{2}\right)}}=\frac{1}{8}$

$\Rightarrow F_2=8 F_1$

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
    A loop is moulded by a constant length current carrying wire and placed in external magnetic field, then torque acts on it does not depends upon

    $(a)$ Shape of loop

    $(b)$ Area of loop.

    $(c)$ Current in loop

    $(d)$ External magnetic field.

     

    View Solution
  • 2
    The current in flowing along the path $A B C D$ of a cube (shown in the left figure) produces a magnetic field at the centre of cube of magnitude $B$. Dashed line depicts the non-conducting part of the cube. Consider a cubical shape shown to the right which is identical in size and shape to the left. If the same current now flows in along the path $D A E F G C D$, then the magnitude of magnetic field at the centre will be
    View Solution
  • 3
    A circular loop of area $0.01\,{m^2}$ carrying a current of $10\, A$, is held perpendicular to a magnetic field of intensity $0.1\,T$. The torque acting on the loop is......$N-m$
    View Solution
  • 4
    One metre length of wire carries a constant current. The wire is bent to form a circular loop. The magnetic field at the centre of this loop is $B$. The same is now bent to form a circular loop of smaller radius to have four turns in the loop. The magnetic field at the centre of this new loop is
    View Solution
  • 5
    If two streams of protons move parallel to each other in the same direction, then they
    View Solution
  • 6
    A thin, straight conductor lies along the axis of a hollow conductor of radius $R$. The two carry equal currents in the same direction. The magnetic field $B$ is plotted against the distance $r$ from the axis. Which of the following best represents the resulting curve?
    View Solution
  • 7
    A moving coil galvanometer has $N$ number of turns in a coil of effective area $A$, it carries a current $I$. The magnetic field $B$ is radial. The torque acting on the coil is
    View Solution
  • 8
    A current carrying long solenoid is placed on the ground with its axis vertical. A proton is falling along the axis of the solenoid with a velocity $v$. When the proton enters into the solenoid, it will
    View Solution
  • 9
    Consider two identical galvanometers and two identical resistors with resistance $R$. If the internal resistance of the galvanometers $R_{ C } < R / 2$

    ($A$) The maximum voltage range is obtained when all the components are connected in series

    ($B$) The maximum voltage range is obtained when the two resistors and one galvanometer are connected in series, and the second galvanometer is connected in parallel to the first galvanometer

    ($C$) The maximum current range is obtained when all the components are connected in parallel

    ($D$) The maximum current range is obtained when the two galvanometers are connected in series and the combination is connected in parallel with both the resistors

    View Solution
  • 10
    For a moving coil galvanometer, the deflection in the coil is $0.05\,rad$ when a current of $10\,mA$ is passed through it. If the torsional constant of suspension wire is $4.0 \times 10^{-5}\,Nm\,rad ^{-1}$, the magnetic field is $0.01\,T$ and the number of turns in the coil is $200$,the area of each turn (in $cm ^2$ ) is :
    View Solution