In figure, two parallel infinitely long current carrying wires are shown. If resultant magnetic field at point $$A$$ is zero. Then determine the value of current $$I$$.

Two circular loops having same radius $$(R=10 \mathrm{~cm})$$ and same current $$\frac{7}{2} \mathrm{~A}$$ are placed along same axis as shown. If distance between their centres is $$10 \mathrm{~cm}$$, find net magnetic field at point $$P$$.

If two protons are moving with speed $$v=4.5 \times 10^5 \mathrm{~m} / \mathrm{s}$$ parallel to each other then find the ratio of electrostatic and magnetic force between them

Assertion : Electron moving perpendicular to B will perform circular motion.

Reason : Force by magnetic field is perpendicular to velocity.