On a straight railway track, absolute levels at point A on two rails are 100.550 m and 100.530 m and the absolute levels at point B 100 m apart are 100.585 m and 100.515 m respectively, the value of twist of rails per metre run, is

Railway engineering is a multi-faceted engineering discipline dealing with the design, construction and operation of all types of rail transport systems. (Source: Wikipedia)

Engineering subjects that are part of railway engineering include:

Mechanical engineering.
Command, control & railway signalling. Office systems design. Data center design. SCADA. Etc
Electrical engineering. Energy electrification. Third rail. Etc
Civil engineering. Permanent way engineering.
Light rail systems.
On-track plant.
Rail systems integration.
Train control systems. Cab signalling.