01․ If two blocks having gains A and B respectively are in series connection, find the resultant gain using block diagram reduction technique?
Rules of block diagram technique
If two blocks having gains A and B respectively
1. Combining blocks in series, overall gain is A*B
2. Combining blocks in parallel , overall gain is A+B
02․ In signal flow graph input node is node having only------------
Terminology of signal flow graph:
- Node: It represents the system variables and is equal to the sum of incoming signals at node.
- Input node or Source node: It is a node having only outgoing branches.
- Output node or Sink node: It is a node having only incoming branches.
- Mixed node or Chain node: It is a node having both incoming and outgoing branches.
03․ When writing a transfer function which of the following loops are not valid loops?
Terminology of signal flow graphs:
Self Loop : It is a path which originates and terminates at the same node.
Note: 1. Self loops on the defined input nodes are not valid loops and should not be considered when writing the transfer function.
2. Self loops on defined output node are valid loops.
04․ Which of the following is the electrical analogous element for displacement in force-voltage analogy?
The electrical equivalents of the mechanical elements in force-voltage analogy are as follows:
Mechanical element ----------- Electrical analogous element
- Mass element (M) ---------- Inductance (L)
- Spring element (K) --------- Inverse capacitance (1/C)
- Dash-pot (B) -------------- Resistance (R)
- Velocity (v) ----------------- Current (i)
- Displacement (x) ----------- Charge (q)
- Force (f) --------------------- Voltage (V)
05․ If two blocks having gains A and B respectively are in parallel connection, find the resultant gain using block diagram reduction technique?
Rules of block diagram technique
If two blocks having gains A and B respectively
1. Combining blocks in series, overall gain is A*B
2. Combining blocks in parallel , overall gain is A+B
06․ Which of the following is/are the characteristics of negative feedback control system?
The characteristics of negative feedback control system are as follows:
1. Accuracy in tracking steady state value
2. Rejection of disturbance signals
3. Reduction in gain at the expense of better stability
4. Low sensitivity to parameter variations
07․ Accurate and reliable output is possible with which of the following system?
Advantages of closed loop control system:
1. The closed loop systems are accurate
2. The closed loop systems are accurate even in the presence of non linearities
3. The sensitivity of the system may be made small to make the system more stable
4. The closed loop systems are less affected by noise
08․ Which of the following combinations is/are correct electrical analogous elements in force-current analogy?
The electrical equivalents of the mechanical elements in Force-Current analogy are as follows:
Mechanical element ----------- Electrical analogous element
- Mass element (M) ---------- capacitance (C)
- Spring element (K) --------- Inverse inductance (1/L)
- Dash-pot (B) -------------- Conductance (G=1/R)
- Velocity (v) ----------------- Voltage (V)
- Displacement (x) ----------- Flux (φ)
- Force (f) --------------------- Current (i)
09․ Which of the following is/are the example of actuator?
The actuator is power amplifying device that produces the input to the plant according to the control signal. The actuator may be pneumatic motor or valve, hydraulic motor or electric motor. Examples of electric motors employed as actuators are DC servomotors, AC servomotors and stepper motors.
10․ In signal flow graph output node is node having only------------
Terminology of signal flow graph:
- Node: It represents the system variables and is equal to the sum of incoming signals at node.
- Input node or Source node: It is a node having only outgoing branches.
- Output node or Sink node: It is a node having only incoming branches.
- Mixed node or Chain node: It is a node having both incoming and outgoing branches.
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