Questions

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

As the inside of the cooker is painted black, heat absorption is more producing heat waves of longer wavelength which cannot escape through glass and hence are trapped inside. Thus the food is cooked.

DPT refers to a class of combination vaccines against three infectious diseases in humans: diphtheria, pertussis, and tetanus.

Pertussis refers to whooping cough.

Marketspace refers to an information and communication based electronic exchange environment. It is a relatively new concept in marketing. Since physical boundaries no longer interfere with buy/sell decisions, the world has grown into several industry specific marketspaces which are integration of marketplaces through sophisticated computer and telecommunication technologies.

Electric current produces a magnetic field. This magnetic field can be visualized as a pattern of circular field lines surrounding a wire.