An electron (mass = $9.1 \times {10^{ - 31}}$ $kg$; charge = $1.6 \times {10^{ - 19}}$ $C$) experiences no deflection if subjected to an electric field of $3.2 \times {10^5}$ $V/m$, and a magnetic fields of $2.0 \times {10^{ - 3}} \,Wb/m^2$. Both the fields are normal to the path of electron and to each other. If the electric field is removed, then the electron will revolve in an orbit of radius.......$m$
Medium
Download our app for free and get startedPlay store
(c) For no deflection in mutually perpendicular electric and magnetic field $v = \frac{E}{B} = \frac{{3.2 \times {{10}^5}}}{{2 \times {{10}^{ - 3}}}} = 1.6 \times {10^8}\,m/s$.
If electric field is removed then due to only magnetic field radius of the path described by electron $r = \frac{{mv}}{{qB}} = \frac{{9.1 \times {{10}^{ - 31}} \times 1.6 \times {{10}^8}}}{{1.6 \times {{10}^{ - 19}} \times 2 \times {{10}^{ - 3}}}} = 0.45\,m$
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 proton (mass $m$ and charge $+e$) and an $\alpha - $particle (mass $4m$ and charge $+2e$) are projected with the same kinetic energy at right angles to the uniform magnetic field. Which one of the following statements will be true
    View Solution
  • 2
    The magnetic field at point, point $P$ will be :-
    View Solution
  • 3
    Two long parallel wires carrying currents $8\,A$ and $15\,A$ in opposite directions are placed at a distance of $7\,cm$ from each other. A point $P$ is at equidistant from both the wires such that the lines joining the point $P$ to the wires are perpendicular to each other. The magnitude of magnetic field at $P$ is $............\times 10^{-6}\,T$. (Given : $\left.\sqrt{2}=1.4\right)$
    View Solution
  • 4
    A current loop $ABCD$ is held fixed on the plane of the paper as shown in the figure. The arcs $ BC$ (radius $= b$) and $DA $ (radius $= a$) of the loop are joined by two straight wires $AB $  and $CD$. A steady current $I$ is flowing in the loop. Angle made by $AB$ and $CD$ at the origin $O$ is $30^o $. Another straight thin wire with steady current $I_1$ flowing out of the plane of the paper is kept at the origin.

    The magnitude of the magnetic field $(B)$ due to the loop $ABCD$ at the origin $(O)$ is :

    View Solution
  • 5
    An alternating electric field, of frequency $f$, is applied across the dees $(\, radius \,\approx\, R)$ of a cyclotron that is being used to accelerate protons $(\,mass \,\approx \, m).$ The operating magnetic field $(B)$ used in the cyclotron and the kinetic energy $(K)$ of the proton beam, produced by it, are given by
    View Solution
  • 6
    Two long wires are hanging freely. They are joined first in parallel and then in series and then are connected with a battery. In both cases, which type of force acts between the two wires
    View Solution
  • 7
    A steady current $I$ flows along an infinitely long hollow cylindrical conductor of radius $R$. This cylinder is placed coaxially inside an infinite solenoid of radius $2 \ R$. The solenoid has $n$ turns per unit length and carries a steady current $I$. Consider a point $P$ at a distance $r$ from the common axis. The correct statement$(s)$ is (are) :

    $(A)$ In the region $0 < r < R$, the magnetic field is non-zero.

    $(B)$ In the region $R < r < 2 R$, the magnetic field is along the common axis.

    $(C)$ In the region $R < r < 2 R$, the magnetic field is tangential to the circle of radius $r$, centered on the axis.

    $(D)$ In the region $r > 2 R$, the magnetic field is non-zero.

    View Solution
  • 8
    A current carrying wire of length $L$ is transformed into a coil of $N$ turns. To achieve maximum magnetic moment, the coil
    View Solution
  • 9
    A long solenoid carrying a current produces a magnetic field $B$ along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is
    View Solution
  • 10
    Which of the following statement is correct :
    View Solution