CUSTOMER_CODE SMUDE DIVISION_CODE SMUDE EVENT_CODE OCTOBER15 ASSESSMENT_CODE MCA1030_OCTOBER15 QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 10114 QUESTION_TEXT Define the following with an example: Empty set, finite and infinite set, equal sets, subsets, powerset SCHEME OF EVALUATION Solution: Empty set: A set which does not contain any element is called an empty set or null set Ex: P={x:1<x<2, x is a natural number} Finite and infinite set: A set which is empty or consists of a definite number of elements is called finite. Otherwise the set is called infinite. Ex: A={1, 2, 3, ….}infinite B={1, 2, 3}finite Equal sets: 2 sets A and B are said to be equal if they have exactly the same elements and we write A=B Ex: Let A ={1, 2, 3, 4}, B={3, 4, 1, 2} Then A=B Subsets: If every element of a set A is also an element of a set b, then A is called a subset of B denoted by A C B Ex: A={1, 2, 3, 4}, B={0, 1, 2, 3, 4, 5} Then A C B Power set: The collection of all subsets of a set A is called the power set of A, denoted by P(A) Ex: A={1, 2} Then P(A)= {∅, {1}, {2}, {1, 2}} QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 74003 QUESTION_TEXT Let p: The south-west monsoon is very good this year. q: Rivers are rising Give the verbal translation of i. ~ [(~p) v (~q)] ii. p q iii. (p v q) v (~p) iv. ~ (p ^ q) v. (~p) ^ (~q) SCHEME OF EVALUATION i. The south-west monsoon is very good this year and rivers are rising. ii. If the south-west monsoon is very good this year then the rivers are rising. iii. The south-west monsoon is very good this year or the rivers are rising or the south-west monsoon is not very good this year. iv. The south-west monsoon is not very good this year or the rivers are not rising. v. The south west monsoon is not very good and the rivers are not rising. (2 5 = 10 marks) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 74005 Explain the concept of Logical Equivalence with example. QUESTION_TEXT SCHEME OF EVALUATION Solution: Two statements S1(p, q, r, …) and S2 (p, q, r, …) are said to be logically equivalent, or simply equivalent if they have the same truth values for all logical possibilities and is denoted by S1(p, q, r, …) = S2 (p, q, r, …) In other words, S1 and S2 are logically equivalent if they have identical truth tables (by identical truth tables we mean the entries in the last column of the truth tables are same. (4 marks) Example: Show that ~(p^q) is logically equivalent to (~p)v(~q) (6 marks) Solution: The truth tables for both the statements are Truth table for ~(p^q) p q (p^q) ~(p^q) T T T F T F F T F T F T F F F T Truth table for (~p)v(~q) p q ~p ~q (~p)v(~q) T T F F F T F F T T F T T F T F F T T T Now, observe that the entries (truth values) in the last column of both the tables are same. Hence, the statement ~(p^q) is equivalent to the statement (~p)v(~q) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 124970 QUESTION_TEXT Explain the concepts of scalar and vector field with example. SCHEME OF EVALUATION (5 marks each) QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 124973 QUESTION_TEXT SCHEME OF EVALUATION Explain the following with example: i. Disjunction ii. Negation iii. Truth table Disjunction If two simple statements p and q are connected by the word ‘or’, then the resulting compound statement “p or q” is called disjunction of statements p and q Example: Form the disjunction of the following simple statements: p : The sun shines. q :It rains. Solution: The disjunction of the statements p and q is given by pν q : The sun shines or it rains. QUESTION_TYPE DESCRIPTIVE_QUESTION QUESTION_ID 124975 QUESTION_TEXT Explain the concept of complex numbers. Briefly explain two properties of complex numbers for addition and multiplication. Let C denote the set of all ordered pairs of real numbers. i.e., C = {(x, y) : x, y R} on this Set C define addition ‘+’ and multiplication ‘.’ by (x1, y1) + (x2, y2) = (x1 + x2 , y1 + y2) → (1) (x1, y1) . (x2, y2) = (x1 x2 – y1y2, x1y2 + x2y1) → (2) Then the elements of C which satisfy the above rules of addition and multiplication are called complex numbers. (2 marks) Properties of addition1. Closure law : If z1 = (x1,y1), z2 (x2, y2) Then from Equation (1) z1+ z2 = (x1,y1) + (x2, y2) = (x1 + x2, y1+y2) Which is also ordered pair of real numbers. Hence z1+z2 C, therefore for every z1, z2 C, z1+z2 C (2 marks) SCHEME OF EVALUATION 2. Associate law : z1+(z2 + z3) = (z1+ z2) + z3 for every z1, z2, z3C (2 marks) Similarly other any 3 properties can be explained. Properties of multiplication1. Closure law : If z1 = (x1, y1), z2 = (x2, y2)C then from (2) (2 marks) z1, z2 = (x1, y1) (x2, y2) = (x1x2 – y1y2, x1y2 + x2y1) Which is also an ordered pair of real number. Hence z1, z2 is also a complex number. Thus for every z1, z2C, z1z2C 2. Existence of identity element : There exists (1, 0) C such that (x, y)(1, 0) = (x.1 –y.0, x.0 + 1.y) = (x, y) for every (x, y) C. Here (1, 0) is called the multiplicative identity element. (2 marks) Similarly other any three properties can be explained.