UGC NET Questions (Paper – 1)

Email is one of the earliest and most widely used internet based communication services, enabling users to exchange messages and attachments electronically. The term is derived from the phrase electronic mail, indicating that it is a digital counterpart of traditional postal mail. Standard textbooks and ICT glossaries expand e mail in this way. Hence, electronic mail correctly completes the abbreviation.

Option A:
Option A is correct because it directly states electronic mail, which is the established and widely accepted expansion of e mail in ICT contexts. It clearly reflects the idea of mail sent through electronic means.

Option B:
Option B, encoded mail, suggests a focus on encryption or coding rather than the general concept of electronic messaging and is not the recognised expansion.

Option C:
Option C, emergency mail, implies a special type of urgent message service rather than the generic communication tool used daily by individuals and organisations.

Option D:
Option D, extended mail, has no standard meaning in ICT and does not appear in authoritative definitions of e mail.

The decimal system uses ten symbols, namely 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Because a positional system's base equals the number of distinct digit symbols, the base of decimal is 10. Therefore, the number of distinct digit symbols in decimal is 10.

Option A:
Option A, 9, would omit one symbol and cannot represent all decimal digits. Since we clearly use ten distinct symbols, this count is too small.

Option B:
Option B is correct because counting from 0 to 9 gives ten unique digits used in everyday arithmetic. This property defines decimal as a base-10 system.

Option C:
Option C, 8, would correspond to an octal system, not to decimal. Octal digits range from 0 to 7 only.

Option D:
Option D, 16, describes the hexadecimal system, which uses digits 0–9 and letters A–F, not the decimal system.

Each octal digit represents 3 binary bits because base 8 equals 2³. For a 12-bit binary number, we need 12 ÷ 3 = 4 octal digits to represent all possible combinations. This grouping covers all 12 bits exactly without wasted digits or missing bits. Therefore, the minimum number of octal digits required is 4, which makes option B correct.

Option A:
Option A, 3 octal digits, cover only 9 bits, which is insufficient for 12-bit numbers.

Option B:
Option B is correct because 4 octal digits represent 12 bits exactly (4×3).

Option C:
Option C, 5 digits, cover 15 bits and are not minimal.

Option D:
Option D, 6 digits, cover 18 bits and are far from minimal.

In hexadecimal, the letters A through F represent decimal values 10 through 15. Since 15 is the highest value represented by a single hex digit, it maps to F. Therefore, the hexadecimal representation of decimal 15 is F₁₆.

Option A:
Option A, E, represents decimal 14, which is one less than 15. It is close but not equal to the required value.

Option B:
Option B, D, stands for decimal 13 in hexadecimal notation. This is smaller than 15 and so cannot be correct.

Option C:
Option C, B, corresponds to decimal 11. It is further away from 15 and therefore not suitable.

Option D:
Option D is correct because F is defined as the symbol for decimal 15 in the hexadecimal system. This mapping is standard and widely used in memory and color code representations.

Everyday counting and most written arithmetic activities use the decimal system. This system is based on ten symbols, 0 through 9, and is therefore called a base-10 or decimal system. Historically it is linked to humans having ten fingers, which made grouping in tens natural. Thus, the decimal system is the usual human counting system.

Option A:
Option A is correct because decimal notation underlies standard arithmetic taught in schools and used in currencies and measurements. Its base 10 structure is reflected in common units such as tens, hundreds and thousands. This makes it the default system for human counting.

Option B:
Option B, binary, is primarily used inside digital circuits and computer processors where two distinct states are easy to implement. It is not the system used in ordinary human counting in daily life.

Option C:
Option C, octal, uses base 8 with digits 0 to 7 and is occasionally used as a shorthand for binary. However, it is not the dominant system for general human activities.

Option D:
Option D, hexadecimal, is a base-16 system widely used in computing for compact representation of binary values, but it is not used for routine human counting tasks.

To find the 2's complement, we first take the 1's complement by inverting each bit and then add 1. For 000101, the 1's complement is 111010. Adding 1 to 111010 gives 111011. Hence, 111011 is the correct 2's complement.

Option A:
Option A, 111001, is not one increment above the 1's complement 111010 and therefore cannot be the 2's complement. Its last two bits do not reflect the required addition.

Option B:
Option B, 111010, is just the 1's complement without adding 1. Since 2's complement requires this extra step, stopping at 111010 is incomplete.

Option C:
Option C, 111000, differs from both the required 1's and 2's complement results. It effectively subtracts value rather than adding one to the inverted pattern.

Option D:
Option D is correct because it accurately follows the two-step process of bit inversion and addition of 1. This pattern is commonly used to represent negative numbers in binary arithmetic.

The decimal 0.25 equals 1/4, which is 2^-2 in terms of powers of 2. In binary, 0.01₂ means 1 in the 2^-2 place and 0 in the 2^-1 place, giving 1/4. Hence 0.01₂ correctly represents 0.25 in decimal.

Option A:
Option A, 0.1₂, represents 1×2^-1 = 1/2, which is 0.5 in decimal. This is greater than 0.25 and unsuitable as its representation.

Option B:
Option B is correct because it places a 1 in the 2^-2 position, giving exactly 1/4. No other fractional positions contribute, so the value is precisely 0.25.

Option C:
Option C, 0.11₂, gives 1/2 + 1/4 = 3/4, which is 0.75 in decimal. This is a much larger value and cannot be equal to 0.25.

Option D:
Option D, 0.001₂, equals 1×2^-3 = 1/8 or 0.125. This is smaller than 0.25 and therefore not the correct representation.

To represent integers from 0 to 1023, we need 1024 distinct codes. A binary pattern of n bits can represent 2^n distinct values. The smallest power of two greater than or equal to 1024 is 2^10. Therefore, 10 bits are required to cover the entire range from 0 to 1023.

Option A:
Option A uses 8 bits, which give 2^8 = 256 patterns. These patterns represent only the range 0 to 255. Since 1023 is much larger than 255, 8 bits are insufficient for this range.

Option B:
Option B uses 9 bits, which give 2^9 = 512 patterns. This allows representation only from 0 to 511. Because 1023 is greater than 511, 9 bits still do not cover the full required range.

Option C:
Option C uses 10 bits, which give 2^10 = 1024 patterns. These patterns can represent all integers from 0 to 1023 without any gap. Hence 10 bits are exactly sufficient and not excessive.

Option D:
Option D uses 11 bits, which give 2^11 = 2048 patterns. This covers a much larger range than necessary for 0 to 1023. It is technically sufficient but not the minimum, so it is not the best answer.

In hexadecimal, the digit F represents decimal value 15. The binary representation of 15 uses four bits all set to 1, because 15 = 8 + 4 + 2 + 1. Therefore, the correct 4-bit binary equivalent of F is 1111₂.

Option A:
Option A, 1101₂, equals 8 + 4 + 0 + 1 = 13, which is less than 15. It does not fully represent the hex digit F.

Option B:
Option B, 1110₂, equals 8 + 4 + 2 + 0 = 14. It is still smaller than 15 and misses the 1's place value.

Option C:
Option C, 1100₂, sums to 8 + 4 = 12 and is even further from 15. It lacks both the 2's and 1's contributions.

Option D:
Option D is correct because 1111₂ sums all four available place values 8, 4, 2 and 1, giving 15. This exactly matches the value of F in hexadecimal.

Each octal digit is converted to a 3-bit binary group. For octal 27₈, the digit 2 becomes 010₂ and the digit 7 becomes 111₂. Combining these groups gives 010111₂. This pattern represents the correct binary equivalent of 27₈.

Option A:
Option A, 001111₂, corresponds to octal 17₈ and not 27₈. Its first group 001₂ represents 1 rather than 2.

Option B:
Option B, 011111₂, would map to octal 37₈, since 011₂ equals 3 and 111₂ equals 7. This is different from the given octal number.

Option C:
Option C, 011011₂, converts back to octal 33₈, as both groups 011₂ equal 3. It clearly does not match 27₈.

Option D:
Option D is correct because 2 maps to 010₂ and 7 maps to 111₂. Concatenating those groups produces the binary representation 010111₂ for 27₈.

The title bar is a prominent graphical element that indicates which document or application the window belongs to. It often contains control buttons for closing, minimising or maximising the window. By reading the title bar, users can quickly identify the content or task associated with each window. Therefore, the component described is the title bar.

Option A:
Option A, tool bar, is a row of icons or buttons that provide quick access to frequently used commands but does not usually display the document or application name.

Option B:
Option B, menu bar, lists menu headings such as File and Edit and is separate from the title bar, though it may appear just below it.

Option C:
Option C is correct because in most graphical systems the bar that shows the window title and includes control buttons is called the title bar.

Option D:
Option D, scroll bar, appears at the edge of a window to navigate through content but has no role in naming the window.

Bandwidth in networking is commonly used to denote the capacity of a communication link to carry data per unit time. It is usually measured in bits per second or its multiples such as Mbps and Gbps. Higher bandwidth allows more information to flow through the channel simultaneously, improving performance. Thus the description of maximum data transfer rate corresponds to bandwidth.

Option A:
Option A, latency, refers to the delay between sending and receiving data, not the volume that can be transmitted per second. A link may have low latency but limited capacity or vice versa. Therefore latency does not express the maximum rate mentioned in the stem.

Option B:
Option B is correct because bandwidth directly quantifies how much data can move through a network connection in a given period. Service providers often advertise their plans using bandwidth figures, highlighting the throughput users can expect. This aligns exactly with the notion of maximum transmission rate stated in the question.

Option C:
Option C, modulation index, is a parameter in analog and digital modulation techniques describing how a carrier is varied by the signal. It does not by itself indicate how many bits per second can be sent over a channel.

Option D:
Option D, attenuation, means the gradual loss of signal strength as it travels through a medium. While it affects quality, it is not a direct measure of data rate capacity.

Decimal 8 can be expressed in octal as one group of eight, which is 10₈. In octal, the place values are 1, 8, 64 and so on, similar to how decimal uses 1, 10 and 100. Thus a single 8 corresponds to 1 in the eights place and 0 in the ones place, giving 10₈.

Option A:
Option A, 7₈, equals seven in decimal, which is one less than 8. It does not include the necessary value in the eights place.

Option B:
Option B, 11₈, equals 1×8 + 1 = 9 in decimal, which is greater than 8. It overshoots the correct value and therefore cannot be the right representation.

Option C:
Option C is correct because 10₈ means 1×8 + 0×1 = 8. This exactly matches the decimal value and follows the octal place value structure.

Option D:
Option D, 8, is not a valid single octal digit since octal digits range from 0 to 7. Writing 8 as a digit in an octal number would violate the base-8 rules.

The decimal system is the standard system used in everyday counting and arithmetic. It employs ten distinct digit symbols from 0 to 9. Because the number of symbols in a positional system equals its base, the base of the decimal system is 10. All place values are powers of 10 such as 1, 10, 100 and 1000.

Option A:
Option A suggests base 2, which is used for binary and involves only digits 0 and 1. This is not consistent with decimal, which uses more symbols. Therefore base 2 cannot be correct.

Option B:
Option B proposes base 4, which would require exactly four distinct digits, often 0 to 3. Since decimal requires ten, base 4 does not match its structure.

Option C:
Option C indicates base 8, which corresponds to the octal system with digits 0–7. It fails to accommodate the digits 8 and 9 that appear in decimal notation.

Option D:
Option D is correct because decimal uses ten symbols and is defined as a base-10 positional system. Every position represents a power of 10, confirming that 10 is its base.

Octal is a base-8 system, and 8 equals 2^3. This means three binary bits can represent exactly one octal digit. To convert binary to octal, we therefore group binary digits in sets of three from the right, converting each group to its octal equivalent.

Option A:
Option A, grouping by 2, gives only 4 different combinations per group, which is insufficient for representing all 8 octal digits. It would not align neatly with base 8.

Option B:
Option B is correct because grouping into threes uses the relationship 8 = 2^3. Each group of three bits corresponds directly to a single octal digit.

Option C:
Option C, grouping by 4, is appropriate for hexadecimal conversion since 16 = 2^4, not for octal. Using four-bit groups for octal would lead to ambiguous mapping.

Option D:
Option D, grouping by 8, would create groups representing 256 different values, which is unnecessarily large for mapping to only 8 octal symbols.