Network Theorems - Short Question and Answer

Network Theorems - Short Question and Answer Points : network theorems short question and answer Q 1. What are the applications of current sources? Ans : Current sources have some applications:
(i) Current sources can too be use to signify equipment for example current-regulated power supplies.
These supplies give a stable current over several limited range of load resistance.
(ii) They can use in definite network study procedures.
(iii) They are use to signify definite devices that show a stable current behavior. Transistors are exemplar of such devices. Q. 2. What do you mean by an ideal voltage source and ideal current source? Ans : Ideal voltage source is one that maintain a steady terminal voltage no matter how greatly current is drawn as of it. Such as and ideal 12 V voltage source in theory maintain 12 V crossways its terminals whether you connect 1 M ohm or 0.01 ohm resistor crossways its terminals. An perfect current source is one which will provide the similar current to some resistance linked to its terminals. Such as a 2 A ideal current source will forever supply 2 A to any value of resistance connected across its terminals. Q. 3. Why do use network theorems and method to solve electrical circuits. Ans : Network theorems and method are regularly use to solve electrical circuits for the following reasons:
(i) During their use, the logical solution becomes extremely easy.
(ii) During their use, a difficult network can be reduced to a easy circuit. Q. 4. What is correct use of the terms network and circuit? Ans : Term network is usually used in reference to an arbitrary arrangement of passive works although circuit frequently implies the presence of active sources and current flow. Though, there is no hard and fast statute for making these distinctions and terms “network” and circuit” are frequently use interchangeably. Q. 5. How does circuit behave under highest power transfer conditions? Ans : Under conditions of maximum power transfer, circuit exhibit the following characteristics:
(i) The load voltage is one-half of the open-circuited voltage at load terminals.
(ii) The effectiveness is 50% only as one-half of the total power generate is dissipate in internal resistance of the source. Q. 6. What do you signify by a bilateral circuit element? Ans : Circuit elements are two-sided if current can pass through them in also direction by equal ease. Q. 7. What is the difference between a mesh and a loop? Ans : A loop is every closed path of a network. Though, a mesh is the majority elementary outline of a loop and cannot be further separated into other loops. Q. 8. How is reference node chosen in nodal analysis? Ans : Choice of reference node in nodal analysis is random but it is frequently convenient to select the reference node as the one have the majority components linked to it. Q. 9. What do you mean by a linear circuit element? Ans : Circuit elements (e.g. resistance and so on.) are linear when they follow Ohm’s law so that repetition the voltage crossways them doubles the current through them. Q. 10. Can you calculate mesh currents? Ans : Branch currents are genuine currents as they actually flow in branches and can be calculated. Though, mesh currents are fictitious and cannot be calculated excluding in those instances where they occur to be identical by branch currents. Q. 10. Where do we use star/delta and delta /star transformation? Ans : There are several networks in which resistances are neither in series nor in parallel. A memorable exemplar is a three terminals network e.g. delta network or star network. In such situations. It is not feasible to make simpler the network through series and parallel circuit rules. Though, converting delta network into star and vice-versa frequently simplifies network and makes it feasible to relate series-parallel circuit method. Q. 11. What is the basis of nodal analysis? Ans : Mesh analysis is base on Kirchhoffs’ voltage law. Though nodal analysis is based on Kirchhoffs’ current law. Q. 12. Why are electronic circuits generally operated under maximum power transfer conditions? Ans : In electronic circuits, it is frequently advantageous to transfer maximum power e.g.
(i) The signal power available at the receiving antenna is very small. It is very important to recover the maximum feasible amount of signal power as of the receiving antenna.
(ii) In the public address system, it is desired that maximum power is transfer as of the amplifier to the speaker (that is. load) in order to function the speaker.
To meet such condition in electronic circuits, we regulate circuit for maximum power transfer. The method is to make load resistance (e.g. speaker) equal to source (e.g. amplifier) resistance. The circuit is then said to be march. Q. 13. What are advantages of nodal analysis over Kirchhoffs’ laws and mesh analysis? Ans : The advantages of nodal analysis over Kirchhoffs laws and mesh analysis are:
(i) Nodal analysis is a suitable approach to circuits that have current sources and conductance sooner than voltage sources and resistances.
(ii) Usually less number of equations are necessary to resolve a circuit by nodal analysis.
(iii) Nodal analysis is suitable in circuits where different voltages, referred to a regular ground, are to be resolute. Q. 14. What are two applications of maximum power transfer theorem? Ans : Two important applications of maximum power transfer theorem are given under:
(i). One more case of maximum power transfer is found in starting of a car engine. The power deliver to the starter motor of car will depend upon efficient resistance of motor and interior resistance of the battery. If the two resistances are equal (as is the case when the battery is fully charged) maximum power will be transfer to motor to turn on engine. This is mainly enviable in winter while every watt that can be extracting as of the battery is desirable with the starter motor to turn on cold engine. If the batter is weak, its internal resistance is elevated and car does not start.
(ii) In electronic circuits, maximum power move is frequently popular. For instance in a public address system, circuit is familiar for maximum power transfer through making load resistance that is speaker) equivalent to source (that is. amplifier) resistance. Q. 16. Why is power system never operate under maximum power conditions? Ans : Under the conditions be maximum power transfer, the effectiveness is low (50%) and there is greater voltage fall in the lines. In a power system, the goal is elevated efficiency sooner than maximum power. For these cause, maximum power transfer is not preferred in a power system.