Remember the truth tables for basic logical operations (and, or, not, implication). A contradiction is always false, and a tautology is always true
For \( S_1 : (p \rightarrow q) \land (p \land \sim q) \), the truth table is:
| \( p \) | \( q \) | \( p \rightarrow q \) | \( p \land \sim q \) | \( S_1 \) |
|---|---|---|---|---|
| T | T | T | F | F |
| T | F | F | T | F |
| F | T | T | F | F |
| F | F | T | F | F |
From the truth table, \( S_1 \) is a Contradiction, as \( S_1 \) is always false.
For \( S_2 : (\sim p \land q) \lor (p \land \sim q) \), the truth table is:
| \( p \) | \( q \) | \( p \land q \) | \( \sim p \land q \) | \( p \land \sim q \) | \( (\sim p \land q) \lor (p \land \sim q) \) | \( S_2 \) |
|---|---|---|---|---|---|---|
| T | T | T | F | F | F | F |
| T | F | F | F | T | T | T |
| F | T | F | T | F | T | T |
| F | F | F | F | F | F | F |
From the truth table, \( S_2 \) is a Tautology, as \( S_2 \) is always true.
Hence:
\( S_1 \) is Contradiction, and \( S_2 \) is Tautology.
If the system of equations \[ (\lambda - 1)x + (\lambda - 4)y + \lambda z = 5 \] \[ \lambda x + (\lambda - 1)y + (\lambda - 4)z = 7 \] \[ (\lambda + 1)x + (\lambda + 2)y - (\lambda + 2)z = 9 \] has infinitely many solutions, then \( \lambda^2 + \lambda \) is equal to:
The output of the circuit is low (zero) for:

(A) \( X = 0, Y = 0 \)
(B) \( X = 0, Y = 1 \)
(C) \( X = 1, Y = 0 \)
(D) \( X = 1, Y = 1 \)
Choose the correct answer from the options given below:
The metal ions that have the calculated spin only magnetic moment value of 4.9 B.M. are
A. $ Cr^{2+} $
B. $ Fe^{2+} $
C. $ Fe^{3+} $
D. $ Co^{2+} $
E. $ Mn^{2+} $
Choose the correct answer from the options given below
Which of the following circuits has the same output as that of the given circuit?
