An alpha particle is projected vertically upward with a speed of 3.0 × 104 kg s–1 in a region where a magnetic field of magnitude 1.0 T exists in the direction south to north. Find the magnetic force that acts on the α-particle.

Given -


Speed of the alpha particle in upward direction,


v = 3 × 104 km/s


since 1Km = 1000m


v = 3 × 107 m/s



Magnetic field, B = 1.0 T



Charge on the alpha particle is given as ,




where e is the charge of an electron.



q = 2 × 1.6 × 10−19 C,


We need to calculate the magnetic force that acts on the α-particl



The direction of magnetic force can be found using Fleming’s left-hand rule.


The direction of the magnetic field is from south to north.



We know, Lorentz force F is given by -



where,


q = charge


v = velocity of the charge


B=magnetic field


and


θ= angle between V and B


Now, magnetic force acting on the α -particle,



Substituting the values



= 2 × 1.6 × 10−19 × 3 × 107 × 1



= 9.6 × 10−12 N


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