The correct option is (A) v1 > v2 > v3 > v4.
Explanation:
In Thomson mass spectrograph. All the charged particle moving with difference velocity but same charge to mass ratio lie on the same parabola. and x ∝ (1/d2)
Hence ion whose deflection is less velocity will be more.
For curve x1 < x2 < x3 < x4
Hence v1 > v2 > v3 > v4