If a positive ion is moving, away from an observer with same acceleration, then the lines of force of magnetic induction will be
closed curves in anti-clockwise direction.
closed curves in clockwise direction.
in the direction of path of positive ion in straight and parallel line, going away from the observer.
in direction of path of positive ion, in straight and parallel lines towards the observer.
A charged particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the charged particle increases to $4$ times its initial value. What will be the ratio of new radius to the original radius of circular path of the charged particle
An electron has mass $9 \times {10^{ - 31}}\,kg$ and charge $1.6 \times {10^{ - 19}}C$ is moving with a velocity of ${10^6}\,m/s$, enters a region where magnetic field exists. If it describes a circle of radius $0.10\, m$, the intensity of magnetic field must be
An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.
$A.$ The electron will experience magnetic force along the axis of the solenoid.
$B.$ The electron will not experience magnetic force.
$C.$ The electron will continue to move along the axis of the solenoid.
$D.$ The electron will be accelerated along the axis of the solenoid.
$E.$ The electron will follow parabolic path-inside the solenoid.
Choose the correct answer from the options given below:
A homogeneous electric field $E$ and a uniform magnetic field $\mathop B\limits^ \to $ are pointing in the same direction. A proton is projected with its velocity parallel to $\mathop E\limits^ \to $. It will
A uniform magnetic field $B$ exists in the region between $x=0$ and $x=\frac{3 R}{2}$ (region $2$ in the figure) pointing normally into the plane of the paper. A particle with charge $+Q$ and momentum $p$ directed along $x$-axis enters region $2$ from region $1$ at point $P_1(y=-R)$. Which of the following option(s) is/are correct?
$[A$ For $B>\frac{2}{3} \frac{p}{QR}$, the particle will re-enter region $1$
$[B]$ For $B=\frac{8}{13} \frac{\mathrm{p}}{QR}$, the particle will enter region $3$ through the point $P_2$ on $\mathrm{x}$-axis
$[C]$ When the particle re-enters region 1 through the longest possible path in region $2$ , the magnitude of the change in its linear momentum between point $P_1$ and the farthest point from $y$-axis is $p / \sqrt{2}$
$[D]$ For a fixed $B$, particles of same charge $Q$ and same velocity $v$, the distance between the point $P_1$ and the point of re-entry into region $1$ is inversely proportional to the mass of the particle