Moving Charges ...

A moving coil galvanometer of resistance $$100 \space \Omega$$ is used as an ammeter using a resistance $$0.1 \space \Omega$$. The maximum deflection current in the galvanometer is $$100 \space \mu A$$.Find the minimum current in the circuit so that the ammeter shows maximum deflection.    

A magnetic field $$ \vec{B} = B_{0}\hat{j} $$ exists in the region $$ a  < x < 2a $$ and $$ \vec{B} = -B_{0}\hat{j} $$ , in the region $$ 2a < x < 3a $$ , where $$ B)_{0} $$ is a positive constant . A positive point charge moving with a velocity $$ \vec{v} = v_{0} \hat{i} $$ , where $$ v_{0} $$ is a positive constant , enters the magnetic field at $$ x = a $$ . The trajectory of the charge in this region can be like 

Two infinite long wires, each carrying current I , are lying along x and y -axis , respectively .A charged particle, having a charge q and mass m, is projected with a velocity u along the straight line OP. the path of the particle is ( neglect gravity) 

Bolt-savart law indicates that the moving electrons (velocity v) produce a magnetic field b such that

Two parallel wires are carrying electric currents of equal magnitude and in the same direction. They exert

The radius of curvature of the path of the charges particles in a uniform magnetic field is directly proportional to

Tick the most appropriate answer.
Which of the following methods is used to magnetize a magnetic without touching it by a magnet?

A magnetic field 

A proton (mass $$=1.67\times 10^{-27} kg$$ and charge $$=1.6\times 10^{-19}C$$) enters perpendicular to a magnetic field of intensity $$2$$ weber $$/m^2$$ with a velocity $$3.4\times 10^7\ m/sec$$. The acceleration of the proton should be

Lorentx force can be calculate dby using the formula