Digital Logic & Number Systems Previous Year Questions (page 3)

Explanation

The two-dimensional view of knowledge management combines strategy (how KM supports the organisation's goals) and content (the knowledge itself). The key takes both.

Explanation

Both statements correctly describe the subject-centred approach: the textbook is the only source, and students memorise facts by repetition. So neither is incorrect.

Explanation

In assessment as learning, students monitor and reflect on their own learning, so it is controlled by the student, not the teacher.

Explanation

NCF 2005 calls multilingualism an integral part of India's linguistic heritage, and a society's culture and attitude toward languages decide whether it stays monolingual or multilingual. Both are correct.

Explanation

Too much water weakens clay and causes cracks in slabs, and children must keep clean and hygienic while working with it. Both precautions apply.

Explanation

Discrimination ignores individual needs, merit and potential, while separate toilets for boys and girls meet genuine needs and are not discrimination. Both are correct.

Explanation

I: 1071 = 2×512 + 0×64 + 5×8 + 7 = (2057)₈, correct. II: (1AF)₁₆ = 256 + 160 + 15 = 431, not 413, so only I is correct.

Explanation

Base 7 uses digits 0-6, so the largest four-digit number is 6666 (7777 is invalid). The smallest four-digit base-8 number is 1000, not 1111. Neither statement is correct.

Explanation

1 + A = 1, and (A + B)(A' + B) = B + AA' = B. So the expression simplifies to B.

Explanation

NOR-ing each input with itself gives A' and B' (2 gates). A third NOR gives (A' + B')' = AB. So 3 NOR gates are needed.

Explanation

The crossing must close if any one or more of the 4 tracks has a train, i.e. output 1 when at least one input is 1, which is the OR function.

Explanation

m0 (000) and m2 (010) group to A'C'. m5 (101) and m7 (111) group to AC. So f = A'C' + AC.

Explanation

An astable multivibrator is free running (no stable state), and a bistable multivibrator is the flip-flop. Both pairs are swapped, so neither is correct.

Explanation

In a sequential file, inserting or deleting a record needs the whole file to be read and rewritten, and locating a record needs on average half the records to be scanned. Both are correct.

Explanation

Boolean algebra expresses the input-output relation of logic diagrams algebraically, which makes analysing and designing digital circuits easier. Both statements are correct.

Explanation

By De Morgan's theorem (x + y)' = x'·y', i.e. x'y'.

Explanation

A NOR gate can be drawn as an OR symbol with an output bubble, or, by De Morgan's law (A + B)' = A'B', as an AND symbol with bubbles on both inputs. Both represent NOR.

Explanation

Permanent (real and personal) accounts are balanced and carried forward to the next period, while temporary (nominal) accounts are closed by transfer to the profit and loss account. Both are correct.

Explanation

The spiral model develops software in a series of evolutionary releases, one per loop. A sequential (waterfall) model delivers the product only once at the end.

Explanation

A Gantt chart can be derived automatically from a PERT chart, but a PERT chart cannot be derived from a Gantt chart because Gantt charts lack task dependencies. Both statements are false.

Explanation

Native internet business models arose on the internet itself, such as library, freeware, information barter and digital product models. The subscription model is transplanted from the real world, so only I is correct.

Explanation

A flow chart can organise notes visually to show the sequence and relation of ideas. Transition devices are linking words used in writing, not a method of organising notes.

Explanation

A teacher must base decisions on sufficient evidence of learning and be sensitive to difficulties some students face in completing tasks. Both need attention.

Explanation

Formative assessment (during learning, to improve it) and summative assessment (at the end, to grade it) are both types of assessment.

Explanation

Sanskrit was the standard (elite) language of Brahmanic society, and Persian is the standard language of Iran. Both statements are correct, so neither is "not correct".

Explanation

Awareness of regional arts and crafts helps children recognise and promote traditional and contemporary art, and sensitises them to India's pluralistic cultural heritage. Both are correct.

Explanation

Gender discrimination can be direct (openly treating someone worse because of gender) or indirect (a neutral-looking rule that disadvantages one gender). Both forms exist.

Explanation

Software evolution covers changes in software architecture (structure and design of systems over time) as well as in programming languages and paradigms used to build them, so both are aspects of evolution.

Explanation

I: 4×343 + 0×49 + 5×7 + 2 = 1372 + 35 + 2 = 1409. II: 1715 = 11×144 + 10×12 + 11 = (BAB)₁₂. Both are correct.

Explanation

EBCDIC is the Extended Binary Coded Decimal Interchange Code, an 8-bit character code used on IBM mainframes.

Explanation

E = 69 = 1000101, X = 88 = 1011000, A = 65 = 1000001, M = 77 = 1001101. Joining the four 7-bit codes gives 1000101 1011000 1000001 1001101, which is option B.

Explanation

E(E + F) = E, and E absorbs DE. D(E + F) = DE + DF, and DE is again absorbed by E. What remains is E + DF.

Explanation

A monostable multivibrator has one stable state and one quasi-stable state: a trigger moves it to the quasi-stable state for a fixed time, after which it returns.

Explanation

B ⊕ B = 0, because XOR gives 1 only when its inputs differ, and here both inputs are always equal.

Explanation

With columns CD = 00, 01, 11, 10: row AB=00 holds m0, m1, m3, m2 → 1 1 _ 1; row 01 holds m4, m5, m7, m6 → only m6; row 11 is empty; row 10 holds m8, m9, m11, m10 → 1 1 _ 1. This matches option A.

Explanation

A flip-flop is a bistable circuit with two stable states, so it stores exactly one bit (0 or 1).

Explanation

The journal records transactions in date order (book of original entry, chronological), while the ledger classifies them account-wise (analytical record). Both statements are correct.

Explanation

Depreciation can be charged by the straight line method (fixed amount each year) or the written down value method (fixed rate on the reducing balance). Both are standard methods.

Explanation

A feasibility study checks whether a project is worth doing, including financial (economic) feasibility and technical feasibility, along with operational and schedule aspects.

Explanation

Monotonic preferences mean more of a good is better, so to keep utility constant a consumer must give up some of one good to get more of the other, which makes indifference curves slope downward.

Explanation

In a teacher-centred approach the teacher controls learning, uses extrinsic motivation (praise, rewards, punishment), and students mainly listen passively and reproduce what was taught. Both are features.

Explanation

Good written feedback starts with praise of what is done well, then points out errors, and asks the student to make corrections rather than simply writing the correct answer. Both points apply.

Explanation

Language learning starts with oral skills: in the LSRW order listening comes first, closely followed by speaking, before reading and writing. The key accepts both as the first step.

Explanation

Listening to and singing poems, and talking about pictures, both give children chances to listen and speak in class.

Explanation

Drama works as a language activity when children have freedom to express themselves and enjoy it, so both freedom and enjoyment are needed.

Explanation

Painters and sculptors both create visual images (visual arts), so both are included.

Explanation

Gender is a socio-cultural construct (correct). Sex is biological, not "systemic"; it is gender that is socially and systemically constructed, so statement II is not correct.

Explanation

P and Q describe the AND gate correctly. For AB + BC + AC you need three AND gates (AB, BC, AC) plus OR gates, so R is also true.

Explanation

NOR is the complement of OR: Y = (A + B)'. The output is 1 only when both inputs are 0.

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.