Anna University Coimbatore 2008 B.E Electrical and Electronics Engineering Control system QB unit 1 - Question Paper

43.Name 2 kinds of electrical analogous for mechanical system.

The 2 kinds of analogies for the mechanical system are
Force voltage and force current analogy

44.What is block diagram?

A block diagram of a system is a pictorial representation of the functions performed by every component of the system and indicates the flow of signals.The basic elements of block diagram arew block, branch point and summing point.

45.What is the basis for framing the rules of block diagram reduction technique?

The rules for block diagram reduction technique are framed such that any modification made on the diagram does not alter the input output relation.

46.What is a signal flow graph?

A signal flow graph is a diagram that represents a set of simultaneous algebraic equations .By taking L.T the time domain differential equations governing a control system can be transferred to a set of algebraic equations in s-domain.

47. What is transmittance?

The transmittance is the gain acquired bythe signal when it travels from 1 node to a different node in signal flow graph.

48.What is sink and source?
Source is the input node in the signal fow graph and it has only outgoing branches. Sink is a output node in the signal flow graph and it has only incoming branches.

49.Define nontouching loop.
The loops are stated to be non touching if they do not have common nodes.

50.Write Masons Gain formula.

Masons Gain formula states that the overall gain of the systm is

T = 1/ ?Sk Pk ?k
k-o.of forward paqths in the signal flow graph.
Pk- Forward path gain of kth forward path
? = 1-[sum of individual loop gains ] +[sum of gain products of allpossible combinations of 2 non touching loops]-[sum of gain products of allpossible combinations of 3 non touching loops]+…
?k - ? for that part of the graph which is not touching kth forward path.

51.Write the analogous electrical elements in force voltage analogy for the elements of mechanical translational system.
Force-voltage e
Velocity v-current i
Displacement x-charge q
Frictional coeff B-Resistance R
Mass M- Inductance L
Stiffness K-Inverse of capacitance 1/C


52.Write the analogous electrical elements in force current analogy for the elements of mechanical translational system.
Force-current i
Velocity v-voltage v
Displacement x-fluxf
Frictional coeff B-conductance 1/R
Mass M- capacitance C
Stiffness K-Inverse of inductance 1/L

53.Write the force balance formula of an ideal mass element .

Earning:   Approval pending.