to provide adequate bond stress

to resist tensile stresses

to impart initial compressive stress in concrete

all of the above

upper part of the beam

lower part of the beam

center

anywhere

Long line method

Freyssinet system

Magnel-Blaton system

Lee-Macall system

The loss of prestress is more in pre-tensioning system than in post-tensioning system.

Pretensioning system has greater certainty about its durability.

For heavy loads and large spans in buildings or bridges, post-tensioning system is cheaper than pretensioning system

none of the above

elastic shortening of concrete

shrinkage of concrete

creep of concrete

loss due to friction