ECAT Pre Engineering Mathematic MCQ Test With Answer for Chapter 1 (Number System)

a.a^-1= a^-1.a = 1 is a

• Commutative law of multiplication A
• Multiplication identity B
• Associative law of multiplication C
• Multiplication inverse D

The square root of every incomplete square is an

• Rational numbers A
• Even numbers B
• odd numbers C
• Irrational numbers D

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

The additive inverse of 1 is

• 1 A
• -1 B
• 0 C
• Does not exist D

• Closure law of addition A
• Closure law of multiplication B
• Commutative law of addition C
• Commutative law of multiplication D

If z₁ =√-36 ,z₂ =√-25,z3 =√-16 then

• 15 A
• 15i B
• -15i C
• -15 D

∀a,b, c ε R ac = bc ⇒ a = b, c ≠ 0 is a

• Symmetric property A
• Cancellation property w.r.t multiplication B
• Reflexive property C
• Transitive property D

If 0 = R, thenthe additive inverse of a is

• 1/9 A
• ^1/-9 B
• a C
• -a D

0 (zero) is

• An irrational number A
• A rational number B
• A negative integer C
• A positive number D

• Associative law of addition A
• Commutative law of addition B
• Additive identity C
• Closure law of addition D

• 
  A
• 
  B
• 
  C
• 
  D

• A positive integer A
• A negative integer B
• A natural number C
• An irrational number D

The real number system contains.

• Positive Numbers A
• Negative numbers B
• Zero C
• (option a, b and c) D

The square root of 2i - 20i is

• +-(5 - 2i) A
• +-(5 + 2i) B
• (5 - 2i) C
• None of these D

• 1 A
• -i B
• i C
• 0 D

• 
  A
• 
  B
• 
  C
• 
  D

Multiplicative inverse of 0 is

• 0 A
• 1 B
• ±1 C
• Does not exist D

• 
  A
• 
  B
• 
  C
• 
  D

i³=

• -1 A
• i B
• -i C
• 1 D

• Associate law of addition A
• Commutative law of addition B
• Additive identity C
• Closure law of addition D

i⁹ =

• i² A
• -1 B
• 1 C
• i D

Any whole number can be written as a product of factors which are

• Odd numbers A
• Prime number B
• Rational number C
• Even number D

1/3 is ______

• A prime number A
• An integer B
• A rational number C
• An irrational number D

(a, b) + (-a, -b) =

• (0,0) A
• (a, b) B
• (-a, -b) C
• (1, 1) D

(a-1)-1 =

• a-1 A
• a B
• -a C
• None of above D

• 
  A
• 
  B
• 
  C
• 
  D

∀ a ε R ∃ o ε R such that a + v = 0 + a = a is property of

• Commutative law of addition A
• Associative law of addition B
• Additive identity C
• Additive inverse D

In R, the additive identity is

• 0 A
• 1 B
• -1 C
• None D

If A = {x / x ∈ R ∧ x² - 16 = 0} then A =

• - x A
• Infinite set B
• Φ C
• {-4,4} D