JEE Mains Model Paper 23

(3) The frequency f the electron =1.6 × 1015 / sec
∴ i =

charge‌on‌electron(q)

time(t)

= charge (q) × frequency of electron (v)
= 6.6 × 10−19 × 6.6 × 1015 = 1.06 × 10−3 amp
Now magnetic filed at the centre is
B =

µ0i

2R

=

4π×107×1.06×103

2×53×1012

= 12.5 tesla