11. The
golden ratio Ï• and its conjugate Ï•’ both satisfy the equation

(A) x

^{3}– x – 1 = 0
(B) x

^{3}+ x – 1 = 0
(C) x

^{2}– x – 1 = 0
(D) x

^{2}+ x – 1 = 0
Answer: C

__Explanation:__
The golden ratio (Greek letter Ï• (phi)) is a
special number approximately equal to 1.618. The Golden Ratio is found when we
divide a line into two parts so that the longer part divided by the smaller
part is also equal to the whole length divided by the longer part.

a/b = (a+b)/a = 1.618...= Ï•

It is exactly equal to (1+√5)/2

12. The
solution of recurrence relation, T(n) = 2T(floor (√n)) + logn is

(A) O(n log log logn)

(B) O(n log logn)

(C) O(log logn)

(D) O(logn log logn)

Answer: D

13. In
any n-element heap, the number of nodes of height h is

(A) less than equal to [n/2

^{h}]
(B) greater than [n/2

^{h}]
(C) greater than [n/2

^{h+1}]
(D) less than equal to [n/2

^{h+1}]
Answer: D

14. A
data file of 1,00,000 characters contains only the characters g-l, with the
frequencies as indicated in table:

using the variable-length code by Huffman
codes, the file can be encoded with

(A) 2,52,000 bits

(B) 2,64,000 bits

(C) 2,46,000 bits

(D) 2,24,000 bits

Answer: D

__Explanation:__
A binary code encodes each character as a
binary string or codeword. We would like to find a binary code that encodes the
file using as few bits as possible, ie., compresses it as much as possible.

In a fixed-length code each codeword has the
same length. In a variable-length code codewords may have different lengths.
Here are examples of fixed and variable legth codes for our problem (note that
a fixedlength code must have at least 3 bits per codeword).

The fixed length-code requires 3,00,000 bits
to store the file.

The variable-length code uses only

(45x1+13x3+12x3+16x3+9x4+5x4)x1000=2,24,000
bits.

15. A
vertex cover of an undirected graph G(V, E) is a subset V

_{1}⊆ V vertices such that
(A) Each pair of vertices in V

_{1}is connected by an edge
(B) If (u, v) ∈ E then u ∈ V

_{1}and v ∈ V_{1}
(C) If (u, v) ∈ E then u ∈ V

_{1}or v ∈ V_{1}
(D) All pairs of vertices in V

_{1}are not connected by an edge
Answer: C

16. In
a fully connected mesh network with n devices, there are ................ physical
channels to link all devices.

(A) n(n–1)/2

(B) n(n+1)/2

(C) 2n

(D) 2n+1

Answer: A

17. The
baud rate of a signal is 600 baud/second. If each signal unit carries 6 bits,
then the bit rate of a signal is .................

(A) 3600

(B) 100

(C) 6/600

(D) None of the above

Answer: A

__Explanation:__
Bit rate=baud rate X bit

18. Match
the following:

**List - I**

a. Data link layer

b. Network layer

c. Transport layer

d. Application layer

**List - II**

i. Flow control

ii. Node to node delivery

iii. Mail services

iv. Routing

**Codes:**

a
b c d

(A) ii i iv iii

(B) ii
iv i iii

(C) ii i iii iv

(D) ii iv iii i

Answer: B

19. An
image is 1024∗800
pixels with 3 bytes/pixel. Assume the image is uncompressed. How long does it
take to transmit it over a 10-Mbps Ethernet?

(A) 196.6 seconds

(B) 19.66 seconds

(C) 1.966 seconds

(D) 0.1966 seconds

Answer: C

__Explanation:__
Time taken to
transmit=(1024x800x3x8)/(10x1000x1000)=1.966 seconds

20. The
.............. measures the relative strengths of two signals or a signal at two
different points.

(A) frequency

(B) attenuation

(C) throughput

(D) decibel

Answer: D

## 0 Comments