# Computer Science and Information Technology - GATE 2011 Paper Solution

In a compiler, keywords of a language are recognized during

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A layer-4 firewall (a device that can look at all protocol headers up to the transport layer) CANNOT

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If two fair coins are flipped and at least one of the outcomes is known to be a head, what is the probability that both outcomes are heads?

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Consider different activities related to email.

m1: Send an email from a mail client to a mail server

m2: Download an email from mailbox server to a mail client

m3: Checking email in a web browser

Which is the application level protocol used in each activity?

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A company needs to develop a strategy for software product development for which it has a choice of two programming languages L1 and L2. The number of lines of code (LOC) developed using L2 is estimated to be twice the LOC developed with L1. The product will have to be maintained for five years. Various parameters for the company are given in the table below

 Parameter Language L1 Language L2 Man years needed for development LOC/10000 LOC/10000 Development cost per man year Rs. 10,00,000 Rs. 7,50,000 Maintenance time 5 years 5 years Cost of maintenance per year Rs. 1,00,000 Rs. 50,000

Total cost of the project includes cost of development and maintenance. What is the LOC for L1 for which the cost of the project using L1 is equal to the cost of the project using L2?

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Let the time taken to switch between user and kernel modes of execution be t1 while the time taken to switch between two processes be t2. Which of the following is TRUE?

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A company needs to develop digital signal processing software for one of its newest inventions. The software is expected to have 40000 lines of code. The company needs to determine the effort in person-months needed to develop this software using the basic COCOMO model. The multiplicative factor for this model is given as 2.8 for the software development on embedded systems, while the exponentiation factor is given as 1.20. What is the estimated effort in person -months?

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Which of the following pairs have DIFFERENT expressive power?

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HTML (HyperText Markup Language) has language elements which permit certain actions other than describing the structure of the web document. Which one of the following actions is NOT supported by pure HTML (without any server or client side scripting) pages?

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Which one of the following is NOT desired in a good Software Requirement Specifications (SRS) document'?

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A computer handles several interrupt sources of which the following are relevant for this question.

• Interrupt from CPU temperature sensor (raises interrupt if CPU temperature is too high)

• Interrupt from Mouse (raises interrupt if the mouse is moved or a button is pressed)

• Interrupt from Keyboard (raises interrupt when a key is pressed or released)

• Interrupt from Hard Disk (raises interrupt when a disk read is completed)

Which one of these will be handled at the HIGHEST priority?

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Consider a relational table with a single record for each registered student with the following attributes.

1. Registration_Num: Unique registration number of each registered student

2. UID: Unique identity number, unique at the national level for each citizen

3. BdnkAccount_Num: Unique account number at the bank. A student can have multiple accounts or joint accounts. This attribute stores the primary account number.

4. Name: Name of the student

5. Hostel_Room: Room number of the hostel

Which of the following options is INCORRECT?

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Which one of the following circuits is NOT equivalent to a 2-input XNOR (exclusive NOR) gate?

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The simplified SOP (Sum of Product) form of the Boolean expression

$\left(P+\overline{)Q}+\overline{)R}\right).\left(P+\overline{)Q}+R\right).\left(P+Q+\overline{)R}\right)$ is

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The minimum number of D flip—flops needed to design a mod-258 counter is

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A thread is usually defined as a "light weight process" because an operating system (OS) maintains smaller data structures for a thread than for a process. In relation to this, which of the following is TRUE?

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K4 and Q3 are graphs with the following structures.

Which one of the following statements is TRUE in relation to these graphs?

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If the difference between the expectation of the square of a random variable $\left(E\left[{X}^{2}\right]\right)$ and the square of the expectation of the random variable ${\left(E\left[X\right]\right)}^{2}$ is denoted by R , then

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The lexical analysis for a modem computer language such as Java needs the power of which one of the following machine models in a necessary and sufficient sense?

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Let the page fault service time be 10 ms in a computer with average memory access time being 20 ns. If one page fault is generated for every 106 memory accesses, what is the effective access time for the memory?