An electron is projected along the axis of circular conductor carrying current '$$\mathrm{I}$$' The electron will experience

A thin ring of radius '$$R$$' meter has charge '$$q$$' coulomb uniformly spread on it. The ring rotates about its axis with a constant frequency of $$f$$ revolution/s. The value of magnetic induction in $$\mathrm{Wb} \mathrm{m}^{-2}$$ at the center of the ring is ($$\mu_0=$$ Permeability of free space)

A particle having a charge $$100 \mathrm{e}$$ is revolving in a circular path of radius $$0.8 \mathrm{~m}$$ with 1. r.p.s The magnetic field produced at the centre of the circle in SI unit is $$\left(\mu_0=\right.$$ permeability of vacuum, $$e= \left.1.6 \times 10^{-19} \mathrm{C}\right)$$

The magnetic field inside a current carrying toroidal solenoid is $$0.2 \mathrm{~mT}$$. What is the magnetic field inside the toroid if the current through it is tripled and radius is made $$\frac{1}{3}^{\text {rd}}$$ ?