An electron is moving along the positive $x$-axis. If the uniform magnetic field is applied parallel to the negative $z$-axis. then

$A.$ The electron will experience magnetic force along positive $y$-axis

$B.$ The electron will experience magnetic force along negative $y$-axis

$C.$ The electron will not experience any force in magnetic field

$D.$ The electron will continue to move along the positive $x$-axis

$E.$ The electron will move along circular path in magnetic field

Choose the correct answer from the options given below:

An electron is projected normally from the surface of a sphere with speed $v_0$ in a uniform magnetic field perpendicular to the plane of the paper such that its strikes symmetrically opposite on the sphere with respect to the $x-$ axis. Radius of the sphere is $'a'$ and the distance of its centre from the wall is $'b'$ . What should be magnetic field such that the charge particle just escapes the wall

If an electron enters a magnetic field with its velocity pointing in the same direction as the magnetic field, then

One proton beam enters a magnetic field of ${10^{ - 4}}$ $T$ normally, Specific charge = ${10^{11}}\,C/kg.$ velocity = ${10^7}\,m/s$. What is the radius of the circle described by it....$m$

A charge having $q/m$ equal to $10^8\, C/kg$ and with velocity $3 \times 10^5\, m/s$ enters into a uniform magnetic field $0.3\, tesla$ at an angle $30^o$ with direction of field. The radius of curvature will be ......$cm$

A charge particle of $2\,\mu\,C$ accelerated by a potential difference of $100\,V$ enters a region of uniform magnetic field of magnitude $4\,m\,T$ at right angle to the direction of field. The charge particle completes semicircle of radius $3\,cm$ inside magnetic field. The mass of the charge particle is $........\times 10^{-18}\,kg$.