T4Tutorials .PK

Chapter 2 . 2. D.C. NETWORK THEOREMS. MCQs

1. . Kirchhoff’s first law is also called:

(A) Mesh


(B) Point


(C) Voltage


(D) Faraday’s




2. . Kirchhoff’s second law is also called:

(A) Mesh


(B) Point


(C) Voltage


(D) Faraday’s




3. . Kirchhoff’s current law applies only:

(A) Close loop in a network


(B) Electric


(C) Electronic


(D) Junction in a network




4. . Kirchhoff’s voltage law applies only:

(A) Close loop


(B) Electric


(C) Electronic


(D) Junction




5. . According to KCL:

(A) Algebraic sum of all currents meeting at a point is zero


(B) Algebraic sum of all currents meeting at a point is not zero


(C) Algebraic sum of all currents meeting at a point is one


(D) All of these




6. . In any electric network, the current coming towards a point is equal to the outgoing current from that point is called:

(A) Point law


(B) Mesh law


(C) Superposition theorem


(D) Both a & b




7. . According to Kirchhoff's law in any closed circuit, the sum of IR drops and EMF is:

(A) Zero


(B) More than zero


(C) Positive


(D) Negative




8. . The resistive drop in a mesh due to current flowing in a clockwise direction must be taken as:

(A) Negative drop


(B) Positive drop


(C) Both a & b


(D) None of these




9. . The resistive drop in a mesh due to current flowing in an anti-clockwise direction must be taken:

(A) Negative


(B) Positive


(C) Neutral


(D) None of these




10. . Single closed path of an electric network is called:

(A) Mesh


(B) Node


(C) One-port network


(D) Two-port network




11. . Such junction or point in a circuit where two or more circuit elements are connected:

(A) Node


(B) Branch


(C) Mesh


(D) Loop




12. . That part of a network, which lies between two junctions, is called:

(A) Node


(B) Branch


(C) Mesh


(D) Loop




13. . The circuit having energy sources is called:

(A) Passive circuit


(B) Linear circuit


(C) Active circuit


(D) Non-linear circuit




14. . Ideal voltage source should have:

(A) Zero Internal Resistance


(B) Infinite Internal Resistance


(C) Large value of e.m.f.


(D) Low value of current




15. . In the superposition theorem, when we consider the effect of one voltage source, all the other voltage sources are:

(A) Shorted


(B) Opened


(C) Removed


(D) Undisturbed




16. . In the superposition theorem, when we consider the effect of one voltage source, all the other current sources are:

(A) Shorted


(B) Opened


(C) Removed


(D) Undisturbed




17. . In the superposition theorem, when we consider the effect of one current source, all the other current sources are:

(A) Shorted


(B) Opened


(C) Removed


(D) Undisturbed




18. . Superposition theorem is not applicable:

(A) Voltage Calculation


(B) Bilateral elements


(C) Power calculations


(D) Passive elements




19. . The concept on which the superposition theorem is based is:

(A) Reciprocity


(B) Duality


(C) Non-linearity


(D) Linearity




20. . Which of the following theorem is applicable for both linear and non-linear circuits?

(A) Superposition


(B) Thevenin’s


(C) Norton’s


(D) None of these




21. . For maximum transfer of power, the internal resistance of the source should be:

(A) Equal to load resistance


(B) Less than the load resistance


(C) Greater than the load resistance


(D) Zero




22. . Does maximum power transfer imply maximum efficiency?

(A) Yes


(B) No


(C) Sometimes


(D) Cannot be determined




23. . Efficiency of power transfer when the maximum transfer of power occurs is:

(A) 100%


(B) 0%


(C) 30%


(D) 50%




24. . The amount of energy supplied by the current in unit time is called:

(A) Electric energy


(B) Friction


(C) Resistance


(D) Electric power




25. . The maximum power is delivered to a circuit when source resistance is ________ load resistance:

(A) Greater than


(B) Equal to


(C) Less than


(D) Greater than or equal to




26. . Does maximum power transfer imply maximum efficiency?

(A) Yes


(B) No


(C) Sometimes


(D) Cannot be determined




27. . Under the condition of maximum power, efficiency is:

(A) 100%


(B) 0%


(C) 30%


(D) 50%




28. . The Thevenin’s voltage is the:

(A) Open circuit voltage


(B) Short circuit voltage


(C) Open circuit and short circuit voltage


(D) Neither open circuit nor short circuit voltage




29. . Thevenin’s resistance is found by:

(A) Shorting all voltage sources


(B) Opening all current sources


(C) Shorting all voltage sources and opening all current sources


(D) Opening all voltage sources and shorting all current sources




30. . Thevenin’s theorem is true:

(A) Linear networks


(B) Non-linear networks


(C) Both linear networks and nonlinear networks


(D) Neither linear networks nor non-linear networks




31. . In Thevenin’s theorem, Vth is:

(A) Sum of two voltage sources


(B) A single voltage source


(C) Infinite voltage sources


(D) 0




32. . Vth is found across the _________ terminals of the network:

(A) Input


(B) Output


(C) Neither input nor output


(D) Either input or output




33. . Which of the following is also known as the dual of Thevenin’s theorem?

(A) Norton’s theorem


(B) Superposition theorem


(C) Maximum power transfer theorem


(D) Millman’s theorem




34. . Which of the following is the right expression for converting from delta to star?

(A) R1 = RaRb / (Ra+Rb+Rc), R2 = RbRc / (Ra+Rb+Rc), R3 = RcRa / (Ra+Rb+Rc)


(B) R1 = Ra / (Ra+Rb+Rc), R2 = Rb / (Ra+Rb+Rc), Rc = / (Ra+Rb+Rc)


(C) R1 = RaRbRc / (Ra+Rb+Rc), R2 = RaRb / (Ra+Rb+Rc), R3 = Ra / (Ra+Rb+Rc)


(D) R1 = RaRbRc / (Ra+Rb+Rc), R2 = RaRbRc / (Ra+Rb+Rc), R3 = RaRbRc / (Ra+Rb+Rc)




35. . Rab is the resistance between terminals A and B, Rbc between B and C, and Rca between C and A. These 3 resistors are connected in delta connection. After transforming to star, the resistance at A will be:

(A) RabRac / (Rab+Rbc+Rca)


(B) Rab / (Rab+Rbc+Rca)


(C) RbcRac / (Rab+Rbc+Rca)


(D) Rac / (Rab+Rbc+Rca)




36. . Resistance at B after delta to star transformation:

(A) Rac / (Rab+Rbc+Rca)


(B) Rab / (Rab+Rbc+Rca)


(C) RbcRab / (Rab+Rbc+Rca)


(D) Rab / (Rab+Rbc+Rca)




37. . Resistance at C after delta to star transformation:

(A) Rac / (Rab+Rbc+Rca)


(B) Rab / (Rab+Rbc+Rca)


(C) RbcRac / (Rab+Rbc+Rca)


(D) Rab / (Rab+Rbc+Rca)




38. . Correct expression for star-delta conversion:

(A) R1 = RaRb/(Ra+Rb+Rc), R2 = RbRc/(Ra+Rb+Rc), R3 = RcRa/(Ra+Rb+Rc)


(B) R1 = Ra/(Ra+Rb+Rc), R2 = Rb/(Ra+Rb+Rc), Rc = / (Ra+Rb+Rc)


(C) R1 = Ra+Rb+RaRb/Rc, R2 = Rc+Rb+RcRb/Ra, R3 = Ra+Rc+RaRc/Rb


(D) R1 = RaRb/Rc, R2 = RcRb/Ra, R3 = RaRc/Rb




39. . Ra is resistance at A, Rb at B, Rc at C in star connection. After transforming to delta, resistance between A and C is:

(A) Ra+Rb+RaRb/Rc


(B) Ra+Rc+RaRc/Rb


(C) Ra+Rb+RaRc/Ra


(D) Ra+Rc+RaRb/Rc




40. . Resistance between A and B after star to delta:

(A) Rc+Rb+RaRb/Rc


(B) Ra+Rb+RaRc/Rb


(C) Ra+Rb+RaRb/Rc


(D) Ra+Rc+RaRc/Rb




41. . Resistance between B and C after star to delta:

(A) Rc+Rb+RcRb/Ra


(B) Rc+Rb+RaRb/Rc


(C) Ra+Rb+RaRc/Rb


(D) Rc+Rb+RcRa/Rb




Exit mobile version