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
$1.8 \times {10^{ - 4}}\,T$
$5.6 \times {10^{ - 5}}\,T$
$14.4 \times {10^{ - 5}}\,T$
$1.3 \times {10^{ - 6}}\,T$
A charged particle is moving in a uniform magnetic field in a circular path. Radius of circular path is $R$. When energy of particle is doubled, then new radius will be
If an electron is going in the direction of magnetic field $\overrightarrow B $ with the velocity of $\overrightarrow {v\,} $ then the force on electron is
A charged particle enters a uniform magnetic field with velocity vector making an angle of $30^o$ with the magnetic field. The particle describes a helical trajectory of pitch $x$ . The radius of the helix is
A uniform beam of positively charged particles is moving with a constant velocity parallel to another beam of negatively charged particles moving with the same velocity in opposite direction separated by a distance $d.$ The variation of magnetic field $B$ along a perpendicular line draw between the two beams is best represented by
A charge of $1\,C$ is moving in a magnetic field of $0.5\,Tesla$ with a velocity of $10\,m/sec$ Perpendicular to the field. Force experienced is.....$N$