An electron (mass = 9 × 10−31 kg, charge = 1.6 × 10−19C) moving with a velocity of 106m/s enters a magnetic field. If it describes a circle of radius 0.1 m, then strength of magnetic field must be
1
4.5 × 10−5T
2
1.4 × 10−5T
3
5.5 × 10−5T
4
2.6 × 10−5T