Moving Charges ...

The magnitude of force per unit length on a wire carrying current $$I$$ at O due to two semi infinite wires as shown in figure, (if the distance between the long parallel segments of the wire being equal to $$L$$ and current in them is $$I$$) is:

A charged particle having charge q experiences a force $$\vec{F}=q(-\vec{j}+\vec{k})N$$ in a magnetic field B when it has a velocity $$v_{1} = 1\hat i \ m/s$$. The force becomes $$\vec{F}=q(\vec{i}-\vec{k})N$$ when the velocity is changed to $$v_{2}=1\hat{j}m/sec$$. The magnetic induction vector at that point is :

A charged particle A of charge q = 2 C has velocity v = 100 m/s. When it passes through point A and has  velocity in the direction shown. The strength of magnetic field at point B due to this moving charge is (r = 2 m).the agle between them is 30.

An $$\alpha $$ particle is moving along a circle of radius $$R$$ with a constant angular velocity $$\omega.$$ Point $$A$$ lies in the same plane at a distance $$2R$$ from the centre. Point $$A$$ records magnetic field produced by $$\alpha $$ particle. If the minimum time interval between two successive times at which $$A$$ records zero magnetic field is $$'t'$$, the angular speed $$\omega ,$$ in terms of $$t$$ is 

A charged particle $$A$$ of charge $$q = 2\ C$$ has velocity $$v = 100 \ m/s$$. When it passes through point $$A$$ and has velocity in the direction shown, the strength of magnetic field at point $$B$$ due to this moving charge is $$(r = 2\ m)$$

A charged particle moves through a magnetic field in a direction perpendicular to it. Then the

A negative test charge is moving near a long straight current carrying wire . A force will act on the test charge in a direction parallel to the direction of the current, if the motion of the charge is in a direction

A charged particle is kept at rest in a uniform magnetic field. If the magnetic field increases with time, 

Two long thin conductors $$10$$ $$cm$$ apart carry currents in the ratio $$1 : 2$$ in the same direction. The magnetic field midway between them is $$2\times 10^{-3}$$ Tesla. The force on $$1$$ metre length of any conductor will be :

A particle of specific charge $$\alpha$$ is projected from origin with velocity $$\overrightarrow{v}=v_0\hat i-v_0\hat k$$ in a uniform magnetic field $$\overrightarrow{B}=-B_0\hat k$$. Find time dependence of velocity of the particle :