A long straight wire AB carries a current of 4A. A proton P travels at 4x10^6ms^-1 parallel to the wire, 0.2m from it and in a direction opposite to the current as shown in figure. Calculate the force which the magnetic field of current exerts on the proton. Also specify the direction of the force.

A long straight wire carries a current of 2A. An electron travels with a velocity of 4xx10^4ms^-1 parallel to the wire 0.1mm from it, and in a direction opposite to the current. What force does the magnetic field of current exert on the moving electron. Charge on electron =1.6xx10^(-19)C.

A current of 10 A flow around a closed path in a circuit which is in the horizontal plane as shown in the figure. The circuit consists of eight alternative arcs of radii r_(1)=0.08m and r_(2)=0.12m . Each subtends the same angle at the centre. An infinitely long straight wire carrying a current of 10 A is passing throgh the entre of the above circuit vertically with the direction of the current being into the plane of the circuit. What is the force acting on the wire at the centre due to the current in the circuit? What is the force acting on the arc AC and the straight segment CD due to the current at the centre?

A straight wire carries a current of 3 A.Calculate the magnitude of the magnetic field at a point 15cm away from the wire. Draw a diagram to show tha direction of the magnetic field.

A long straight wire in the horizontal plane carries a current of 50 A in north to south direction. Give the magnitude and direction of B at a point 2.5 m east of the wire.

Two long parallel wires are 0.4 m apart in air and carry currents of 5 A and 12 A respectively. Calculate the force on each metre of the wire, fi the currents are in the same direction .