Two bar magnets are placed close to each other with their opposite poles facing each other. In absence of other forces, the magnets are pulled towards each other and their kinetc energy increases. Does it contradict our earlier knowledge that magnetic forces cannot do any work and hence cannot increase kinetic energy of a system?

Two currents- carrying wires may attract each other. In absence of other forces, the wires will move towards each other increasing the kinetic energy . Does it contradict the fact that the magnetic force cannot do any work and hence cannot increase the kinetic energy?

Magnetic lines of force never intersect each other . What is the reason ?

Two long bar magnets are placed with their axes coinciding in such a way that the north pole of the first magnet is 2.0cm from the south pole of the second. If both the magnets have a pole strength of 10 Am , find the force exerted by one magnet on the other.

Two charged particles placed at a separation of 20 cm exert 20 N of coulomb force on each other. What will be the force if the separation is increased to 25 cm?

Two electrons move parallel to each other with equal speeds v. The ratio of magnetic and electrical forces between them is ______ .

A block of mass M is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force F. The kinetic energy of the block increases by 20J in 1s.

Two long wires a and b, carrying equal currents of 10*0A, are placed parallel to each other with a separation of 4*00 cm between them as shown in figure. Find the magnetic field B at each of the points P,Q and R.

What will happen to the potentail energy of the system ? If (i) Two same charged particles are brought towards each other (ii) Two oppositely charged particles are brought towards cach other

Two wires carrying equal currents i each, are placed perpendicular to each other, just avoiding a contact. If one wire is held fixed and the other is free to move under magnetic forces, what kind of motion wil results?

Two short bar magnets have magnetic moments 1.20 Am^(2) and 1.00 Am^(2) respectively . They are kept on a horizontal table parallel to each other with their north poles pointing towards the south . They have a common magnetic equator and are separated by a distance of 20.0 cm. The value of the resultant horizontal magnetic induction the mid point O of the line joining their centers is (Horizontal components of Earth's magnetic induction is (3 xx 10^(-5) Wb m^(-2) ) ...............