JEE Advanced Model Paper 9 with solutions for online practice

When the magnetic field is suddenly switched off then, induced electric field will begenerated because of changing flux. Therefore the induced electric field at a distance ‘a’from the centre is given by
E =

a

2

dB

dt

..... (1)
According to Newton’s second law
∫ Fdt = pf - pi ..... (2)
∫ qE dt = pf−pi
∫ q

q

2

dB

dt

= pf−pi = q

a

2

B0