If a magnet is dropped through a long thick walled vertical copper tube, the magnet attains constant velocity after some time. Explain.

Consider a metallic pipe with an inner radius of 1cm . If a cylindrical bar magnet of radius 0.8 cm is dropped through the pipe ,it takes more time to come down than it takes for a similar unmagnetised cylindrical iron bar dropped through the metalic pipe. Expain .

A metergauge train runs northwards with a constant speed of 22 m/s on a horizontal track.The vertical component of the earth's magnetic field at that place is 3 xx 10^-4 T . the emf induced in its axle is

A particle of mass m and charge q is accelerated through a potential differece V to a velocity vecv towards south. The particle enters a region with both a magnetic field vecB (pointing eastwards) and electric field vecE (pointing downwards). The particle travels with a constant velocity through this region. The potential difference V through this region should be equal to

A current of IA, flows along an infinitely long Staight thin walled tube. The magnetic induction at any point inside the tube is

A metallic ring of mass m and radius i (ring being horizontal) is falling under gravity in a region having a magnetic field . If z is the vertical direction, the z- component of magnetic field is B_z = B_0(1 + lambda z) If R is the resistance of the ring and if the ring falls with a velocity v, find the power lost in the resistance . If the ring has reached a constant velocity, use the conservation of energy to determine v in terms of m, B , lambda and acceleration due to gravity g.

A stone is thrown vertically upwards from the ground with a velocity 15 m/s. At the same instant a ball is dropped from a point directly above the stone from a height of 30 m. At what height from the ground will the stone and the ball meet and after how much time? (Use g= 10 m//s^2 for ease of calculation).

A body starting with an initial velocity of 5 m//s , moves with a uniform acceleration of 2 m//s^(2) . After some time it attains a velocity of 13 m//s . Find the distance covered by the body during this period.

A body starting with an initial velocity of 4 m//s , moves with a uniform acceleration of 0.5 m//s^(2) . After some time its velocity becomes 6 m//s . Calculate the time taken by the body to attain this velocity and the distance covered by it during this time interval.

A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s ^-1 about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring .A constant and uniform magnetic field of 0.5 T parallel to the axis exists eveywhere. Calculate the emf developed between the centre and the ring

Two drops of equal size are falling vertically through air with a constant terminal velocity of 0.15 cm//s. What should be the velocity if these drops coalesce to from one drop ?