Answer to Question #311208 in Electricity and Magnetism for Lin

Question

An ion of charge, q=+1.60 x 10¹9 C entering a uniform magnetic field, B-0.3 T

with a velocity, v-6.5 x 10³ ms as shown in FIGURE 3(b). The mass of the ion is 1.76 x 107 kg.

Copy FIGURE 3(b). Sketch the path of the ion in the magnetic field.

[1 mark]

[6 marks]

Calculate the distance from the hole that the ion strikes the plate.

(ii)

(iii) Another ion of twice the mass but has the same charge and velocity enters. the magnetic field. Show on the same figure in (i) above, the path of this ion.

Answer 1

$E=Fl,$

$\frac{mv^2}2=qvBl,$

$l=\frac{mv^2}{2qvB}=\frac{mv}{2qB}=12\cdot 10^{-3}~m.$