Antennas Assignment 1

 Antenna Fundamentals

    1)A cell tower antenna needs to cover an area with 120° angular coverage in horizontal plane. The radiation pattern of the antenna should be

 Isotropic

 Omnidirectional

 Directional

 Cannot be determined from the given data

      2)Antenna A and Antenna B have directivities of 2 dBi and 6 dBi in a given plane, respectively. Which of the two antennas would have larger   HPBW?

 A

 B

 Both A and B will have the same HPBW

 Cannot be determined from the given data

      3)The directivity of an antenna is 9.6 dBi. If the half power beam width (HPBW) is 70° in one plane, the HPBW in the orthogonal plane is, approximately:

 50°

 65°

 70°

 85°

4)An antenna has efficiency of 80%. If the directivity of the antenna is 7 dBi, then its gain will be, approximately:

 4 dBi

 5.6 dBi

 6 dBi

 7 dBi

    5)The E-field of the wave radiated by an antenna has two orthogonal components with amplitudes of 0.5 V/m and 0.3 V/m. If the phase difference between the two components is 90°, the polarization of the wave is:

 Linear

 Left hand circular

 Elliptical

 Right hand circular

 6)In a 50 Ω system, if input impedance of an antenna is 68 Ω, the corresponding value of VSWR is, approximately:

 1.15

 1.22

 1.36

 1.68

7) In a 50 Ω system, if input impedance of an antenna is (50 – j25) Ω at 2.45 GHz, the percentage power reflected from the antenna will be, approximately:

 94.12 %

 75.75 %

 24.25 %

 5.88 %

8)AGSM 900 cell tower antenna with 15 dBi gain is transmitting 20 W of power. The power density at a distance of 100 m in the direction of maximum radiation is 5 mW/ m2. What will be the value of power density at a distance of 200 m?

 0.25 mW/m2

 0.5 mW/m2

 1.25 mW/m2

 2.5 mW/m2

    9)Two identical transmitting and receiving antennas are located at a distance of 1 km. If power transmitted is 25 dBm at 10 GHz and received power is -65 dBm, the approximate gain of each antenna is:

 11.2 dBi

 13.2 dBi

 17.5 dBi

 21.3 dBi

10)The diameter of a parabolic dish antenna (with efficiency η = 60%) for 40 dBi gain at 10 GHz is:

 0.62 m

 0.85 m

 1 m

 1.23 m

Answers: 1)b,2)c,3)b,4)c,5)c6)b7)b8)c9)a10)c 

Digital Circuits: Assignment 12:

Answers are at end...........

1.

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1 point

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1. C 

2. D

3. C

4. B

5. B

6. B

7. D

8. A

9. B

10. D

11. A

12. C

13. C

14. C

15. C

The Joy of Computing using Python: Programming Assignment 12:

Programming Assignment-1: Holes

Let us assume paper as the plane and a letter as a curve on the plane, then each letter divides the plane into regions. For example letters "A", "D", "O", "P", "R" divide the plane into two regions so we say these letters each have one hole. Similarly, letter "B" has two holes and letters such as "C", "E", "F", "K" have no holes. We say that the number of holes in the text is equal to the total number of holes in the letters of the text. Write a program to determine how many holes are in a given text.

Input Format:The only line contains a non-empty text composed only of uppercase letters of English alphabet.
Output Format:output a single line containing the number of holes in the corresponding text.
Example-1

Input:

DRINKEATCODE

Output:
5


Explanation:
D R A O D has one hole hence total number of holes in the text is 5.

Program:

ip=input() c=0 H1=["A", "D", "O", "P", "R",'Q'] H2=["B"] #H0=['C','E','F','G','H','I','J','K','L','M','N','S','T','U','V','W','X','Y',"Z"] for i in ip: if i in H1: c+=1 elif i in H2: c=c+2 print(c,end='')

Programming Assignment-2: Smallest Palindrome

Given a string S having characters from English alphabets ['a' - 'z'] and '.' as the special character (without quotes). 
Write a program to construct the lexicographically smallest palindrome by filling each of the faded character ('.') with a lower case alphabet.

Definition:

The smallest lexicographical order is an order relation where string s is smaller than t, given the first character of s (s1 ) is smaller than the first character of t (t1 ), or in case they

are equivalent, the second character, etc.

For example "aaabbb" is smaller than "aaac" because although the first three characters

are equal, the fourth character b is smaller than the fourth character c. 

Input Format: 
String S

Output Format: 
Print lexicographically smallest palindrome after filling each '.' character, if it

possible to construct one. Print -1 otherwise.

Example-1

Input:
a.ba

Output:
abba


Example-2:

Input:
a.b

Output:
-1

Explanation: 
In example 1, you can create a palindrome by filling the '.' character by 'b'.In example 2, it is not possible to make the string s a palindrome.

Program 2:

x=list(input()) l=len(x) if l%2==1: a=x[0:int(l/2)] b=x[int(l/2)+1:] b=b[::-1] Y="alk" for i in range(len(a)): if a[i]=="." and b[i]!=".": a[i]=b[i] elif b[i]=="." and a[i]!=".": b[i]=a[i] elif a[i]=="." and b[i]==".": a[i]="a" b[i]="a" elif a[i]!=b[i] or b[i]!=a[i]: print("-1",end="") Y='fls' break if Y!="fls": b=b[::-1] s=a+["a"]+b print("".join(s),end="") else: a=x[0:int(l/2)] b=x[int(l/2):] b=b[::-1] Y="alk" for i in range(len(a)): if a[i]=="." and b[i]!=".": a[i]=b[i] elif b[i]=="." and a[i]!=".": b[i]=a[i] elif a[i]=="." and b[i]==".": a[i]="a" b[i]="a" elif a[i]!=b[i] or b[i]!=a[i]: print("-1",end="") Y='fls' break if Y!="fls": b=b[::-1] s=a+b print("".join(s),end="")

Programming Assignment-3: Letters

Write a program that accepts a sentence and calculate the number of upper case letters and lower case letters.

Input Format:
The first line of the input contains a statement.

Output Format:
Print the number of upper case and lower case respectively separated by a space.

Example:

Input:
Hello world!

Output:
1 9

Program 3:

ip=input() up=0 lw=0 for i in ip: if i.islower() : lw+=1 elif i.isupper() : up+=1 print(up,lw,end='')

The Joy of Computing using Python: Assignment 12

1. In the point distribution method of page rank algorithm, at each iteration, each node shares its pagerank value by

 Randomly choosing one of its outgoing links and sharing all its pagerank value to the node connected to that link

 Dividing its pagerank value equally to all the outgoing links

 Dividing its pagerank value randomly to all the outgoing links

 Dividing its pagerank value to all the outgoing links with the value given being proportional to their outdegree

Ans: b

1 point

2. In random walk method, what is the next step when a sink node is encountered in the underlying graph?

 random node is chosen out of all the given node

 The node with maximum number of incoming links is chosen

 The node with maximum number of outgoing links is chosen

 The process stops at this stage

Ans: a

1 point

3. According to Google Page rank algorithm, rank of a page depends on:

 Number of pages it is referring to

 Number of pages referring to it

 Rank of pages it is referring to

 Rank of pages referring to it

Ans: b

1 point

4. Which of the following is not true about Collatz Conjecture?

 If the previous term is even, the next term is one half the previous term

 If the previous term is odd, the next term is 3 times the previous term

 If the previous term is odd, the next term is 3 times the previous term plus 1

 No matter what value of n, the sequence will always reach 1

Ans: b

1 point

5. State True or False.

The sequence based on 3n+1 problem will always reach 1.

 True

 False

Ans: True

1 point

6. What is the sequence obtained according 3m+1 algorithm for m=9?

 28,14,7,22,11,34,17,52,26,13,40,20,10,5,16,8,4,2,1

 28,14,7,22,11,34,52,26,13,40,20,10,5,16,8,4,2,1

 28,14,7,22,11,17,52,26,13,40,20,10,5,16,8,4,2,1

 28,14,7,22,11,34,17,52,26,13,40,20,10,5,16,8,4,2,1

Ans: a

1 point

7. Consider the following statements:
Statement (a): Random Walk method requires lesser number of iterations to calculate accurate PageRank as compare to Points Distribution method
Statement (b): Points Distribution method requires lesser number of iterations to calculate accurate PageRank as compare to Random Walk method

 Statement a is correct

 Statement b is correct

 None of the above

Ans: c

1 point

8. In the web graph, nodes are the web pages. What are the edges?

 Network Connections

 Links to other web pages

 URLs

 None of the above

Ans: b