The number of four-digit numbers strictly greater than 4321 that can be formed using the digits 0,1,2,3,4,5 (repetition of digits is allowed) is :

The height of a right circular cylinder of maximum volume inscribed in a sphere of radius 3 is

A circuit connected to an ac source of emf e = e₀sin(100t) with t in seconds, gives a phase difference of $$\pi $$/4 between the emf e and current i. Which of the following circuits will exhibit this ?

Two very long, straight, and insulated wires are kept at 90° angle from each other in xy-plane as shown in the figure. These wires carry currents of equal magnitude I, whose directions are shown in the figure. The net magnetic field at point P will be :