AP EAMCET Engineering 22 Sep 2020 Shift 1 Paper

Charge on helium nucleus,
q=2e=2×1.6×10−19
=3.2×10−19C
r=0.8m,T=2.5s
Current associated due to one rotation of helium nucleus,
I=‌

9

T

=‌

3.2×10−19

2.5

=1.28×10−19A
∴ Magnetic field at the centre of the circle formed by helium nucleus,
B‌‌=‌

µ0I

2r

=‌

4π×10−7×1.28×10−19

2×0.8

‌‌=3.2π×10−26T
which is nearest to 4π×10−26T.