### Applications of constraints in classical physics

In classical mechanics, a constraint is a relation between coordinates and momenta (and possibly higher derivatives of the coordinates). In other words, a constraint is a restriction on the freedom of movement of a system of particles.
Types of constraint

1.First class constraints and second class constraints
2.Primary constraints, secondary constraints, tertiary constraints, quaternary constraints.
3.Holonomic constraints, also called integrable constraints, (depending on time and the coordinates but not on the momenta) and Non-holonomic constraints
4.Pfaffian constraints
5.Scleronomous constraints (not depending on time) and rheonomous constraints (depending on time).
6.Ideal constraints: those for which the work done by the constraint forces under a virtual displacement vanishes.

A very Good explanation by :
Dr. M Ramegowda
Dept. of Physics
Govt. College (Autonomous), Mandya

### COMMON COLLECTOR CONFIGURATION OF A TRANSISTOR

COMMON COLLECTOR CONNECTION

In  this  configuration  the  input  is  applied  between the  base  and  the  collector and  the  output  is  taken  from  the  collector  and  the  emitter.  Here  the  collector  is common to both the input and the output circuits as shown in Fig.

Common Collector Transistor Circuit

In  common  collector  configuration  the  input  current  is  the  base current  IB  and  the output current is the emitter current IE. The ratio of change in emitter current to the  change in the base current is called current amplification factor.

It is represented by

COMMON COLLECTOR CIRCUIT

A test  circuit  for determining the  static characteristic  of an NPN transistor is shown in Fig. In this circuit the collector is common to both the input and the output circuits.   To   measure   the   base   and   the   emitter   currents,   milli   ammeters   are connected in series with the base and the emitter circuits. Voltmeters are connected   across the input an…