Two identical particles of mass m carry a charge Q, each. Initially one is at rest on a smooth horizontal plane and the other is projected along the plane directly towards first particle from a large distance with speed v. The closest distance of approach be .

One end of a string of length t is connected to a particle of mass m and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed v the net force on the particle (directed towards the centre) is : T is the tension in the string. [Choose the correct alternative].

Two particles , each of mass m and charge q, are attached to the two ends of a light rigid rod of length 2 R . The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod

Two identical point charges of charge Q are kept at a distance r from each other. A third point charge is placed on the line joining the above two charges, such that all the three charges are in equilibrium. Calculate the magnitude and location of the thrid charge.

A circular ring of radius R with uniform positive charge density lambda per unit length is located in the y z plane with its center at the origin O. A particle of mass m and positive charge q is projected from that point p( - sqrt(3) R, 0,0) on the negative x - axis directly toward O, with initial speed V. Find the smallest (nonzero) value of the speed such that the particle does not return to P ?

A point particle of mass M is attached to one end of a massless rigid non-conducting rod of length L. Another point particle of the same mass is attached to the other end of the rod. The two particles carry charges +q and -q respectively. This arrangement is held in a region of a uniform electric field E such that the rod makes a small angle theta (say of about 5 degree) with the field direction, fig. Find an expression for the minimum time needed for the rod to become parrallel to the field after it is set free.

Two identical ball bearings in contact with each other and resting on a frictionless table are hit head-on by another ball bearing of the same mass moving initially with a speed V. If the collision is elastic, which of the following (Fig. 6.14) is a possible result after collision ?

Two point electric charges of value q and 2q are kept at a distance d apart from each other in air. A third charge Q is to be kept along the same line in such a way that the net force action on q and 2q is zero. Calculate the position of charge Q in terms of q and d.

A particle of mass m and charge (-q) enters the region between the two charged plates initially moving along x-axis with speed v_x. The length of plate is L and an uniform electric field E is maintained between the plates. Show that the vertical deflection of the particle at the far edge of the plate is qEL^2//(2m v_x^2) .

Two identical ball bearing in contact with each other and resting on a frictionless table are hit head on by another ball bearing of the same mass moving initially with a speed V shown in the figure. If the collision is elastic, which of the folloiwng shown in the figure is a possible result after collision ?

Two identical plane metallic surfaces A and B are parallel to each other in air separated by a distance of 1 cm as shown in the fig. Surface A is given a postive potential 10 V and the outer surface of B is earthend What is the magnitude and direction of the uniform electric field between points Y and Z?