ECAT Pre Engineering MCQ Test With Answer for Chapter 1 Mathematics

The multiplicative 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

• 15 A
• 15 i B
• -15 i C
• -15 D

i is equal

• (1 , 0) A
• (0 , 1) B
• (1 , 1) C
• (0 , 0) D

• 
  A
• 
  B
• 
  C
• None of these D

Every natural number is

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

What is the conjugate of -7 -2i ?

• -7 + 2i A
• 7 +2i B
• 7 -2i C
• √53 D

Any recurring decimal represents a

• Irrational no A
• Integer B
• Rational no C
• None of these D

In R the right cancellation property w.r.t. addition is

• 
  A
• 
  B
• 
  C
• 
  D

∀a,b ε R, ab = be is a

• Commutative law of multiplication A
• Closure law of multiplication B
• Associative law of multiplication C
• Multiplicative identity D

If z₁ = 1 + 2i, z₂ = 3 + 4i then

• z₁ > z₂ A
• z₁ = z₂ B
• z₁ < z₂ C
• None of these D

The multiplicative inverse of -3i is

• 3i A
• -3i B
• -1/3i C
• 1/3 i D

• 
  A
• 
  B
• 
  C
• 
  D

The additive identity of real number is

• 1 A
• 2 B
• 1/2 C
• 0 D

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

• 1 A
• 3 B
• 2-i C
• -1 D

• 
  A
• 
  B
• 
  C
• 
  D

The square root of 2i - 20i is

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

(a+bi) - (c+di)=

• (a+b) = (c+d) A
• (a+c) + i(b+d) B
• (a - c) + (c- d)i C
• (a - c)+ (b - d)i D

• are real no A
• both are not real B
• are imaginary no C
• both are imaginary D

• Associative property of addition A
• Associative property of multiplication B
• Commutative property of addition C
• Commutative property of multiplication D

∀a,b,c∈R, a >b ∧ b>c ⇒ a >c is

• Trichotomy property A
• Transitive property B
• Symmetric property C
• Additive property D

In set builder notation the set {0,1,2,........100} can be written as

• {x / xε B ∧ x ≤ 100} A
• {x / x ∈ W ∧ x < 101} B
• {x / x ∈ Z ∧ x < 101} C
• The set of first 100 whole numbers D

A subset of set of complex number whose elements are of the form (a,0) is called

• Real number A
• Complex number B
• Rational number C
• Irrational number D

i⁹ =

• i² A
• -1 B
• 1 C
• i D

• 
  A
• 
  B
• 
  C
• 
  D

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

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

• 
  A
• 
  B
• 
  C
• 
  D

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