# Networks - GATE practice papers - Electronics & Communication

Here, you can read Networks multiple choice questions and answers with explanation.

1)   Which theorems do not support the similarity of handling dependent and independent current and voltage sources ?

A. Thevenin's & Norton's Theorems
B. Superposition & Norton's Theorems
C. Maximum Power transfer & Reciprocity Theorems
D. Millman's & Tellegen's Theorem
Manipulation of independent and dependent voltage and current sources is almost similar in almost all types of theorems except Thevenin's , Norton's and superpositon theorems especially for the calculation of equivalent impedances.
(Marks : 02)

- Published on 19 Oct 15

a. A & B
b. C & D
c. A & C
d. B & D
 Answer  Explanation ANSWER: A & B Explanation: No explanation is available for this question!

2)   What is the function of dependent source in the circuit diagram shown below?

(Marks : 02)

- Published on 19 Oct 15

a. It delivers 256 W
b. It absorbs 256 W
c. It delivers 512 W
d. It absorbs 512 W
 Answer  Explanation ANSWER: It absorbs 512 W Explanation: From the given network,Power = V x I = (2 Ix) x Ix = 2 I2xSince Ix = 16AP = 2 x (16)2 = 512 W (absorption)Hence, the total power of about 512W is absorbed in the given circuit.

3)   What will be the value of time constant for the network shown below?

(Marks : 02)

- Published on 19 Oct 15

a. 5RC
b. 4RC
c. (4/5) RC
d. RC /5
 Answer  Explanation ANSWER: (4/5) RC Explanation: By replacing the voltage source in terms of internal impedance, the equivalent circuit is shown below.From the above equivalent network, it is obvious that Req = (R x 4R) / 5R = 4R /5 Also, the time constant (τ) = Req x C = (4 /5) RC

4)   Which statements represent the properties of a tree according to the  network graph theory ?

A1 : There exists only a single path between any pair of nodes.
A2 : The rank of a tree is similar to the rank of graph
A3: A tree does not contain any node on the graph
A4 : A tree comprises all closed paths
(Marks : 02)

- Published on 19 Oct 15

a. A1 & A2
b. A3 & A4
c. A1, A2 , A 3 & A4
d. None of the above
 Answer  Explanation ANSWER: A1 & A2 Explanation: Only the statements A1 & A2 satisfy the properties of a tree. The statements A3 & A4 are not precise because a tree contains all the nodes on the graph and does not contain any closed path.

5)   Which two-port device has a provision to simulate the equivalent values of  inductance? (Marks : 01)
- Published on 19 Oct 15

a. Inductor
b. Capacitor
c. Transformer
d. Gyrator
 Answer  Explanation ANSWER: Gyrator Explanation: Gyrator is a four terminal device whose coefficient value is dependent on the Op-amp parameters as well as externally connected R,C values. It exhibits a unique feature of impedance inversion phenomenon due to which the input impedance is capacitive for an inductive load impedance and vice-versa. In addition to this, simulation of equivalent inductance values is also a major function performed by a gyrator

6)   How many number of trees are possible for a network possessing 'n' nodes? (Marks : 01)
- Published on 19 Oct 15

a. 2n-1
b. 2n+2
c. n[1/ n+2]
d. nn-2
 Answer  Explanation ANSWER: nn-2 Explanation: For any kind of network, the number of trees can be always determined on the basis of its branches and nodes. This can be implied as, No. of trees = nn-2where, n represents the nodes & n-2 represents the number of branches in a tree

7)   Which element of graph theory specifies a  subgraph of a graph by allowing the incidence of exactly two branches at each node? (Marks : 01)
- Published on 19 Oct 15

a. Twig
b. Path
c. Loop