Questions

Q:

What are the different Adder circuits you studied?

Answer

Adders are generally of five types:


1.Ripple Carry Adder:


The Ripple carry adder(RCA) consists of a building block named Half Adder(HA) which is cascaded to form a Full Adder(FA). These buildingblocks HAs and FAs are also the building blocks of all types of adders.The n full adders are cascaded to form n bit RCA.


The full adder has three input pins(input Ai,input Bi,carryin Ci) and two output pins(Sum and Ci+1).Its equations are:


Sum=Ai^Bi^Ci


Ci+1=Ai.Bi+Bi.Ci+Ai.Ci


 


2. Carry Lookahead Adder:


The Carry Lookahead Adder(CLA) reduces the delay as that in RCA. Let Gi=Ai.Bi, and Pi=Ai^Bi, then Ci+1=Gi+Pi.Ci.


The expressions for Sum and Ci+1 is then defined completely in terms of input pins rather wait for input carry to appear.


 


3. Carry Select Adder:


The carry select adder uses duplicate modules for each combination of input carry(i.e. 1 and 0).The multiplexers then select the appropriate sum and carry output according to the carry output of the preceding stages.


 


4. Carry Skip Adder:


The carry skip adder are as fast as carry lookahead adders which are the fastest adders but its spped decreases to about 20-30% if input operands are 64-bit or more. In these adders we divide the input bit stream into various blocks and make use of two observations:


-if each element of the two bit streams are unequal,i.e. Ai!=Bi than the carry input of the block is equal to the carry input.


-if each element of the two bit streams are equal,i.e. Ai=Bi than the carry input of the block is opposite of the carry input.


 


5. Carry Save Adder:


The carry save adder reduces the addition of three elements into addition of two elements,i.e. if you want sum of nine numbers it reduces it into sum of six numbers. In first step the sum of three numbers is calculated without bothering for the carry.During the second step only carry is calculated which is then added to the generated sum to give the required sum. 

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Subject: Hardware

0 3529
Q:

How many gold medal have been won by India in the Olympics so far

A) 4 B) 6
C) 8 D) 10
 
Answer & Explanation Answer: C) 8

Explanation:
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Filed Under: Sports

6 3528
Q:

Dogs are herbivores. True or false

A) TRUE B) FALSE
Answer & Explanation Answer: B) FALSE

Explanation:

Yes, Dogs are not Herbivores. They are omnivores as they eat both plants and meat.


 


Hence, the given statement that Dogs are herbivores is FALSE.

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Subject: Animals and Birds
Exam Prep: AIEEE , Bank Exams
Job Role: Analyst , Bank Clerk , Bank PO

6 3527
Q:

Who has written the book ' The Famished Road '

A) Zolla Emile B) VS. Naipaul
C) Ben Okri D) Din Mani
 
Answer & Explanation Answer: C) Ben Okri

Explanation:
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Filed Under: Books and Authors

2 3525
Q:

The book " The Vijay Mallya Story " has been written by _____

A) Vijay Mallya B) Gopinath
C) Giriprakash D) Siddharth Mallya
 
Answer & Explanation Answer: C) Giriprakash

Explanation:
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Filed Under: Books and Authors
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

9 3525
Q:

Where is the canal "Chain of Rocks" located?

A) Virginia B) Illinois
C) California D) None
 
Answer & Explanation Answer: B) Illinois

Explanation:

Chain of Rocks is located in illinois

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Filed Under: World Geography

2 3524
Q:

What is the capital of Mongolia?

A) Ulaanbaatar B) Monaco
C) Maputo D) Kathmandu
 
Answer & Explanation Answer: A) Ulaanbaatar

Explanation:

Ulaanbaatar is the capital of Mongolia

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Filed Under: Country Capitals

10 3523
Q:

Which company made the first tea bags?

Answer

Tetley

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Subject: World History

9 3522