A proton and an alpha particle are accelerated from rest through the same potential difference and then enter the same uniform magnetic field perpendicularly. What is rα/rₚ?
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A proton and an alpha particle are accelerated from rest through the same potential difference and then enter the same uniform magnetic field perpendicularly. What is rα/rₚ?

G1 Physics · Accepted Answer

r=√(2mK)/(qB) with K=qV, so r∝√(m/q). For alpha, (m/q)/(mₚ/e)=4/2=2, hence the ratio is √2.