Question

A proton is projected with a uniform velocity '$v$' along the axis of a current carrying solenoid. Then:

• A. The proton will be accelerated along the axis.
• B. The proton path will be circular about the axis.
• C. The proton move along helical path.
• D. The proton will continue to move with velocity '$v$' along the axis.

Answer 1

The correct option is D The proton will continue to move with velocity '$v$' along the axis.

The magnetic field due to a solenoid at the axis is along the axis. Hence, if a proton projected with a velocity '$v$' along the axis, its velocity will be parallel to the magnetic field. As there is no component of velocity of proton perpendicular to the magnetic field, net force on the proton will be zero and the proton will continue to move along the axis with velocity v.