EMF can be produced either by change of flux through a particular area kept in a magnetic field in a particular interval of time ( called self induced emf) or by the motion of any conducting rod in manetic fied....

emf in volts

Bcoz the emf which is to be measured is less than emf of driving cell....

yes indused emf is also called motional emf.

If an open coil is subjected to a variable magnetic field, at the ends of the coil a potential difference is induced which is called induced emf.

If a coil is connected to an emf source and switched on, the rising current will produced an variable magnetic field which in turn produces an emf. It is called back emf.

EMF - band - ended in 2009.