Computer Science Previous Year Questions (page 34)

Explanation

Calling event.preventDefault() in the submit handler cancels the browser's default action, the form submission. stopPropagation() only stops the event from bubbling.

Explanation

fwrite() writes a block of data, and fseek() sets the file position pointer. ftell() only returns the current position; rewind() is the function that moves to the beginning.

Explanation

PNG supports an alpha channel, so images can be transparent. JPG has no transparency, and BMP normally does not either.

Explanation

<ol> creates an ordered (numbered) list. <ul> creates an unordered list, and <li> marks each list item.

Explanation

Debits: cash 54,750 + purchases 62,000 + sales return 1,600 + Y 21,500 + furniture 3,000 + wages 5,200 = 1,48,050. The credits also total 1,48,050.

Explanation

Credit sales = closing debtors + cash collected + discount allowed − opening debtors = 60,000 + 6,00,000 + 10,000 − 50,000 = ₹6,20,000.

Explanation

Closing cash = 5,50,000 + 5,25,000 − 4,50,000 = ₹6,25,000. Unpaid rent and salaries are outstanding expenses and do not reduce the cash balance.

Explanation

Gunn diodes (and klystrons, magnetrons) generate microwaves, which are used in radar for aircraft navigation.

Explanation

2 bytes = 16 bits. An unsigned integer has no sign bit, so it holds 0 to 2¹⁶ − 1 = 0 to 65535.

Explanation

The inner printf prints "Tata Consultancy" first and returns the number of characters printed, 16 (4 + space + 11). The outer printf then prints 16.

Explanation

sinh t = (eᵗ − e⁻ᵗ)/2. Replacing D² by 1 in 1/(D² − 4) gives 1/(1 − 4), so the particular integral is −sinh t / 3.

Explanation

Check x = 3, y = 2, z = 1: 15 + 2 + 3 = 20, 6 + 10 + 2 = 18 and 9 + 4 + 1 = 14. All three equations are satisfied.

Explanation

MOV is an executable instruction. DB, END and ORG are assembler directives, which tell the assembler what to do but produce no machine instruction.

Explanation

A doubly linked list has both next and prev pointers, so it can be traversed forward and backward. It uses more memory than a singly linked list.

Explanation

"variable" is not a C keyword. sizeof, signed and auto are all reserved keywords in C.

Explanation

Current ratio = current assets ÷ current liabilities. It measures short-term liquidity, that is, the ability to pay short-term debts.

Explanation

The highest derivative is d³y/dx³, so the order is 3. The key gets degree 4 by raising both sides to the 4th power. Strictly, the cos(d²y/dx²) term means the degree is not defined.

Explanation

In a skew-symmetric matrix aᵢⱼ = −aⱼᵢ, so the diagonal is all zeros. Option B has a12 = 1, a21 = −1; a13 = 2, a31 = −2; a23 = −4, a32 = 4.

Explanation

16 KB = 2¹⁴ bytes, so 14 address lines, A0 to A13, are needed to select every location.

Explanation

The Intel 8085 is an 8-bit microprocessor. The 8086 and 68000 are 16-bit processors, and the 80386 is 32-bit.

Explanation

The mode "wb" opens a file for writing in binary mode. The mode string is "w" followed by "b", not "bw" or "binary".

Explanation

In a microprogrammed control unit, control memory stores the microprograms (sequences of microinstructions) that create the control signals.

Explanation

The Earth absorbs sunlight and re-radiates the energy at long wavelengths as infrared (heat) radiation. Greenhouse gases trap this radiation.

Explanation

Matrix × (1, 1, 0) = (3 − 1, 7 − 5, 6 − 6) = (2, 2, 0) = 2 × (1, 1, 0), so the eigenvalue is 2.

Explanation

A sole proprietorship needs almost no legal formalities or registration cost, so it is the simplest and cheapest business form to set up.

Explanation

Smileys and emoticons show feelings and tone, such as happiness or a joke, which plain text cannot show in instant messages.

Explanation

Statement A is false: the bases of a histogram's rectangles lie on the horizontal (x) axis, which shows the class intervals. Frequencies are on the vertical axis.

Explanation

Netiquette (network + etiquette) is the set of rules for polite, responsible behaviour on the internet.

Explanation

The P/E ratio = market price per share ÷ earnings per share. It shows how many rupees investors pay for each rupee of earnings.

Explanation

System software (OS, drivers, utilities) runs and manages the hardware. Application software (word processors, browsers) does specific tasks for users.

Explanation

A Type I error is rejecting the null hypothesis when it is actually true (a false positive). Accepting a false null hypothesis is a Type II error.

Explanation

System software manages the computer hardware and provides a platform. Application software runs on it to help users do specific tasks.

Explanation

IM apps carry personal messages and data that can be intercepted, leaked or misused, so data security is a privacy concern.

Explanation

The ALU (Arithmetic Logic Unit) performs arithmetic such as addition and subtraction, and logical operations such as AND, OR and comparisons.

Explanation

Behavioural objectives state the observable change expected in pupils after learning, which makes teaching focused and evaluation possible.

Explanation

The Programme of Action (1992) under NPE 1986 asked for textbooks to be revised to remove gender bias and for teachers and staff to receive gender-sensitisation training.

Explanation

A lesson plan states the objectives first and then the teaching procedure (the steps and activities used to reach them).

Explanation

Role-play puts students in realistic situations, which builds problem-solving, empathy and communication skills.

Explanation

Language across the curriculum develops reading, writing, listening and speaking in every subject, not only in language classes.

Explanation

Magnifiers enlarge text and images, which helps students with low vision. Braille slates are mainly for blind students.

Explanation

The integrated principle links learning areas into meaningful activities, for example combining language, art and daily living skills, instead of teaching isolated facts.

Explanation

Assessment collects information about learning, and evaluation interprets that information to judge how far the learning outcomes were achieved.

Explanation

Intuition is direct, sudden knowing, without conscious reasoning, that comes with a strong feeling of certainty.

Explanation

Personality differences come mainly from heredity and from family and social environment such as parenting and socioeconomic status. School infrastructure has the least influence.

Explanation

A FULL (OUTER) JOIN keeps every row from both tables and puts NULL where no match exists. LEFT or RIGHT JOIN keep unmatched rows from only one side, and INNER JOIN keeps only matching rows.

Explanation

A digital certificate, signed by a Certificate Authority, binds the owner's identity to a public key and states the validity period. The private key is never put in a certificate.

Explanation

Paging divides logical memory into pages, and the page table maps each page number to a physical frame number, which translates logical addresses into physical addresses.

Explanation

The UDP header has only four fields: source port, destination port, length and checksum. Sequence numbers belong to TCP, which needs them for reliable, ordered delivery.

Explanation

An XOR gate needs at least two inputs, and it outputs 1 when the inputs differ (an odd number of inputs are 1). A one-input XOR gate does not exist.

Explanation

ICMP Destination Unreachable (type 3) is sent by a router or host when a packet cannot be delivered to the destination network, host, protocol or port.