ECAT Pre Engineering MCQ Test With Answer for Chapter 1 Mathematics

If z₁ = (a,b), z₂=(c,d), then z₁ z₂ = -------------------

• (ac,bd) A
• (ac+bd, ad-bc) B
• (ac-bd , ad+bc) C
• (ac-bd , ad-bc) D

The multiplicative inverse of 0 is

• 1 A
• -1 B
• 0 C
• Does not exist D

• 
  A
• 
  B
• 
  C
• 
  D

The value of x, and y, when (x + iy)²= 5 + 4i

• X = 2, y = -1 A
• X = -2, y=1 B
• X = 2, y = -1 C
• X = 2, y = 2 D

• real number A
• complex number B
• rational number C
• irrational number D

The multiplicative inverse of (a,b) is

• 
  A
• 
  B
• 
  C
• 
  D

• A natural number A
• A rational number B
• An irrational number C
• A whole number D

If in a set of real no a is additive identity then

• a+a = 2a A
• a+a = 1 B
• a+a = 0 C
• None of these D

(a^-1)^-1=

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

• 
  A
• 1 B
• 
  C
• -1 D

• A rational number A
• A irrational number B
• An even integer C
• A factor of 36 D

Name the property used in 4 x (5 x 8) = ( 4 x 5) x 8

• Associative property of addition A
• Associative property of multiplication B
• Additive identity C
• Multiplicative identity D

√-1 b=

• b A
• 2 B
• 2b C
• None of these D

The product of complex numbers (a,b) and (c,d) is

• (ac, bd) A
• (ac-bd, ad+bc) B
• (ab,cd) C
• (ac+bd,ad-bc) D

The square root of 2i - 20i is

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

• 
  A
• 
  B
• 
  C
• 
  D

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

• 
  A
• 
  B
• 
  C
• 
  D
• 
  E

Name the property used in 4 + 9 = 9 + 4

• Associative property of addition A
• Commutative property of addition B
• Distributive property C
• Additive identity D

• 
  A
• 
  B
• 
  C
• 
  D

What is the conjugate of -6 -i

• -6 +i A
• 6 + i B
• -6 -i C
• 6 -i 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

Every real number is

• A complex number A
• A rational number B
• A natural number C
• A prime number D

• 15 A
• 15 i B
• -15 i C
• -15 D

• Rational A
• Irrational B
• Even C
• Odd D

The real number system contains.

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

• Additive property of inequality A
• Commutative property B
• Additive inverse C
• Additive identity D

If a and b are real numbers then a+b is also real number this law is called

• associative law of addition A
• closure law of addition B
• Distributive law of addition C
• Commutative law of addition D

π is ______

• A complex number A
• A rational number B
• A natural number C
• An irrational number D

In R the number of identity elements w.r.t.'.' is

• One A
• Two B
• Three C
• Four D