# DC machines Important MCQ type questions For GATE

DC machines Important MCQ type questions For GATE

Q1. Capacity of a dry cell, is
1. more when it supplies current continuously.
2. more when it supplies current intermittently.
3.  not affected by the type of discharge.
4.  none of the above.

Q2. The emf of primary cell depends upon the
1. physical dimensions.of a cel.
2.  nature of electrolyte.
3. nature of electrode.
4.  both (b) and (c).

Q3. Maxwell's loop current method of solving electrical networks
1.  uses branch currents.
2.  utilizes Kirchhoff s voltage law.
3. is cofined to single-loop circuits.
4.  is a network reduction method.

Q4. Superposition theorem is applicable for
1.  Linear circuits only.
2.  Non-linear circuits only.
3. Linear and non-linear circuits both.
4.  None of these.

Q5. Nodal analysis is based on
1.  KCL.
2.  KVL
3.  both
4.  law of conservaion of energy.

Q6. In nodal analysis, if there are N nodes in the circuit, then how
many equations will be written to solve the network?
1.  N-1
2.  N+1
3.  N
4.  N-2

Q7. Point out the wrong statement. In the node voltage technique of
solving networks, choice of a reference node does not
1.  affect the operation of the circuit.
2.  change the voltage across any element.
3. after the pd between any pair of nodes.
4.  affect the voltages of various nodes.
Q8. Consider the following statements on mesh and nodal analysis:
1. Networks that contain many series-connected elements,voltage sources or meshes having common current sources(super meshes) are more suitable for mesh analysis than for nodal analysis.
2.  Networks with parallel connected elements, current sources or nodes connected by voltage sources are more suitable for nodal analysis than mesh analysis.
3.  A circuit with fewer nodes than meshes is better analysed using mesh analysis, while a circuit with fewer meshes, than nodes is better analyzed using nodal analysis.
Which of the statements given above are correct?
1. 1 and 2 only
2. 2 and 3 only.
3. 1 and 3 only.
4.  1,2 and 3

Q9. while thevenizing a circuit between two terminals, vth is equal
to
1. short-circuit terminal voltage.
2.  open-circuit terminal voltage.
3. net voltage available in the circuit.
4.  emfof the battery nearest to the terminals.

Q10. while determining Rth of a circuit
1. voltage and current sources should be left as they are.
2. all sources should be replaced by their source resistances.
3. all independent current and voltage sources are short-circuited.
4. none of the above.

Q11. Which of the folowing statements is/are correct?
1.  Norton's equivalent resistance is the same as Thevenin's equivalent resistance RTH
2.  Norton's equivalent is the curent equivalent of the network.
3. The load is connected in parallel to the Norton's equivalent resistance and Norton's equivalent current source,
4.  all of the above.

Q12. A human nerve cell has an open-circuit voltage of 80 mV and it
can deliver a current of 5 nA through a 6 M ohm load. What is the
maximum power available from the cell?
1.  0.16 nW
2. 1.6 nw
3.  1.6 W
4.  1.6 pW

Q13. A load is connected to an active network. At the terminals to which the load is connected, R= 102 and Vh60 V. Then maximum power supplied to the load is
1. 360 w
2.  60 W
3. 90 W
4.  10 W

Q14. For a linear network containing generators and impedances, the
ratio of the voltage to the current produced in other loop is the
same as the atio of voltage and cunent obtained if the positions of the voltage source and the ammeter measuring the current are interchanged. The network theorem is known as
1.  Millman's theorem.
2.  Norton's theorem.
3. Tellegen's theorem.
4.  Reciprocity theorem.
Q15. Consider the two circuits I and II shown in the given figures
Which of the following statements regarding the current flowing
through the ammeters A and Aa is correct?
1. The currents in A and A are of the same value and equal 0.25 A.
2.  The currents in A and A, are respectively 0.25 A and 2.5 A
3.  The curent in both the ammeters is of the same vaiue and equals 2.5A.
4.  The currents in A, and A2 are respectively 2.5 A and 0.25 A.

Q16. In a balanced Wheatstone bridge, if the positions of detector and source are interchanged, the bridge will still remain balanced. This inference can be drawn from
1.  reciprocity theorem
2.  duality theorem
3. compensation theorem
4.  equivalence theorem

Q17. For a π  network with admittances Ya and Yb are shunt arms and Yc as the series arm, the values of y11, Y12 and y22 will be
respectively
1.  (Ya+Yc) ,Yb, Yc
2.  (Ya + Yc), -Yc ,( Yb+Yc)
3. Ya , (Yb+Yc) , -Yc
4.  Ya, -Yc, Yb

Q18. For a two-port symmetrical bilateral network, if A = 3 and
B=1ohm ,  the value of parameter C will be
1.  4 s
2.  6 s
3.  8 s
4.  16 s

Q19. Pole of a network is a frequency at which
1.  network function becomes zero.
2.  network function becomes infinite.
3. (network function becomes unity.
4.  none of these.

Q20. A pole of driving point admittance function implies
1.  zero current for a finite value of driving voltage.
2.  zero voltage for a finite value of driving current.
3. an open circuit condition.
4.  none of these

Q21. The lowest and the highest critical frequencies of an R-L driving- point impedance are, respectively
1.  a zero, a pole. .
2.  a zero, a zero.
3.  a pole, a pole.
4.  a pole, a pole.

Q22. The first and the last critical frequencies (singularities) ofa driving point impedance function of a passive network having two kinds
of elements, are a pole and a zero respectively. The above property
will be satisfied by
1.  RL network only
2.  RCnetwork only
3. LCetwork only
4.  RC as well as RL networks

Q23. The first and last critical frequency of an RC-driving point
impedance function must respectively be
1.  a zero and a pole.
2.  a zero and a zero.
3.  a pole and a pole.
4.  a pole and a zero.

Q24. The poles and zeroes of an all-pass network are located in which
part of the s-plane?
1. Poles and zeroes are in the right half s-plane.
2.  Poles and zeroes are in the left half s-plane.
3.  Poles in right half and zeroes in left half of s-plane.
4.  Poles in the left half and zeroes in right half of s-plane.