List of top Physics Questions on Motion in a Magnetic Field

Two particles of masses \(m_1\) and \(m_2\) having charges \(q_1\) and \(q_2\) respectively are projected with the same velocity in a region of uniform magnetic field \(\vec{B}\) pointing vertically upward. If they describe circular paths as shown in the figure, one may conclude that :

An alpha particle (mass \(6.4 \times 10^{-27} \text{ kg}\) and charge \(3.2 \times 10^{-19} \text{ C}\)) having \(8.0 \text{ MeV}\) energy, enters a region of a uniform magnetic field of \(0.5 \text{ T}\). If the field is directed perpendicular to the velocity of the particle, find the radius of the circular path described by the particle. Mention the condition under which the particle in this region (i) describes a helical path, and (ii) goes straight undeviated.

Arrange the following steps in the chronological order, when a charged particle enters perpendicularly into a uniform magnetic field. (A) The charged particle starts moving in a circular path. (B) Net work done by the field is zero. (C) The speed of the charged particle remains constant but its direction changes. (D) A force acts perpendicular to both the velocity of the charged particle and the magnetic field. Choose the correct answer from the options given below:

A deuteron and an alpha particle with the same kinetic energy move in circular paths under the effect of the same magnetic field. The ratio of the radii \((r_d:r_\alpha)\) of their trajectories is

A charged particle accelerated through a potential difference of V volts acquires a speed u. The particle is then made to enter perpendicularly in a uniform magnetic field B. The radius of the circular path followed by the charged particle will be proportional to