ECAT Mathematics Chapter 1 Number System Online Test

If ∀a,b ε R,then a +b  ε  R is a property

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

Every real number is

• a positive integer A
• a rational number B
• a negative integer C
• a complex number 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

Which of the following has the same value as i¹¹³?

• i A
• -1 B
• -i C
• 1 D

Associative law of multiplication

• ab = ba A
• a(bc) = (ab) c B
• a(b+c) = ab + ac C
• (a + b)c = ac + bc D

• x A
• 
  B
• y C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

if Z1 = 1+i, Z2= 2+3i, then |Z2 -Z1| =

• √3 i A
• √7 B
• -2-i C
• √5 D

If P is a whole number greater than 1, which has only P and I are factors. Then P is called

• Wholw number A
• Prime number B
• Even number C
• Odd number D

In (x + iy) x is the known as

• Imaginary part of complex number A
• Real part of complex number B
• Complex number C
• None of above D

The multiplicative inverse of -3i is

• 3i A
• -3i B
• -1/3i C
• 1/3 i D

• 
  A
• 
  B
• 
  C
• 
  D

The negative square root of 9 can be written as:

• -√9 A
• √9 B
• √18 C
• -√18 D

∀x,y∈R and x> 0 , y>0, if x > y

• 
  A
• 
  B
• 
  C
• None of these D

• 
  
  
  A
• 
  B
• 
  C
• 
  D

2/9,5/7∈ R,(2│9)(5│7)=10/63∈R this property is called

• Associative property A
• Identity property B
• Commutative property C
• Closure property w.r.t multiplication D

If ∀a,b ε R,then a +b  ε  R is a property

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

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

• One A
• Two B
• Three C
• Four D

i² =

• 1 A
• 2 B
• -1 C
• 0 D

What is the conjugate of -7 -2i ?

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

The set of rational number is represented by

• W A
• R B
• Q' C
• Q
  
  
  D

Union of the sets of rational and irrational numbers is called 6th set of

• Natural numbers A
• Real numbers B
• Whole numbers C
• Prime numbers D

What is the conjugate of -6 -i

• -6 +i A
• 6 + i B
• -6 -i C
• 6 -i D

• Principle of equality of fractions A
• Rule for product of fraction B
• Rule for quotient of fraction C

If a is any real number and a = a is called

• symmetric property A
• Trichotomy Properties B
• Transitive Property C
• Reflexive Properties D

Every prime number is also

• Rational number A
• Even number B
• Irrational number C
• Multiple of two numbers D

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

√25 is a number

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

6 is

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