A 10 eV electron is circulating in a plane at right angles

A 10 eV electron is circulating in a plane at right angles to a uniform field at magnetic induction 10^-4 Wb/m² (= 1.0 gauss). The orbital radius of the electron is

K.E. of electron = 10 eV

⇒	1	mv² = 10 eV
	2

⇒	1	(9.1 × 10^-31)v² = 10 × 1.6 × 10^-19
	2

⇒ v² =	2 × 10 × 1.6 × 10^-19
	9.1 × 10^-31

⇒ v² = 3.52 × 10¹² ⇒ v = 1.88 × 10⁶ m
Also, we know that for circular motion

	mv²	= Bev ⇒ r =	mv	= 11 cm
	r		Be