Question

Protons and singly ionized atoms of U²³⁵ and U²³⁸ are passed in turn (which means one after the other and not at the same time) through a velocity selector and then enter a uniform magnetic field. The protons describe semicircles of radius 10 mm. The separation between the ions of U²³⁵ and U²³⁸ after describing semicircle is given by-

• A. 60 mm
• B. 30 mm
• C. 2350 mm
• D. 2380 mm

Answer 1

Answer: (A)

60 mm

Answer 2

r₂₃₅ = $\frac{235m_{p}v}{eB}$ = 235 × 10 = 2350 m

r₂₃₈ = $\frac{238m_{p}v}{eB}$= 2380 mm The separation between the ions of U²³⁵ & U²³⁸

= 2 (r₂₃₈ – r₂₃₅)

= 2 × (2380 – 2350)

= 60 mm