ECAT Mathematics Chapter 1 Number System

π is ______

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

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

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

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

4/√49 is a

• Irrational Number A
• Prime Number B
• Rational number C
• Whole number D

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

Multiplicative inverse of 0 is

• 0 A
• 1 B
• ±1 C
• Does not exist D

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

• √3 i A
• √7 B
• -2-i C
• √5 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

∀x,y,z ∈ R and z 0,then

• x > y ⇒ xz > yz A
• x<y ⇒ xz < yz B
• x < y ⇒ xz > yz C
• None of these D

3/4 is ______

• An odd number A
• An even number B
• A natural number C
• A rational number D

• 
  A
• 
  B
• 
  C
• 
  D

If Z = (1,2), then Z^-1= ?

• (0.2, 0.4) A
• (-0.2, 0.4) B
• (0.2, -0.4) C
• (-0.2, -0.4) D

Geometrically the modulus of a complex number represents its distance from the

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

The negative square root of 9 can be written as:

• -√9 A
• √9 B
• √18 C
• -√18 D

i^-(4n+2) = -------------------------------

• 1 A
• i B
• -1 C
• -i D

If z = (x,y) , then  z ̅  =

• (-x,y) A
• (x,-y) B
• (-x, -y) C
• None of these D

The set of rationals numbers between 0 and I is

• Finite A
• Null set B
• Infinite C
• None of these D

∀x,y∈ R and x < 0, y < 0, which one is true 

• xy < o A
• xy = o B
• xy > o C
• None of these D

• Commutative property of addition A
• Closure property of addition B
• Additive inverse C
• Associative property w.r.t. to addition D

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

The set { 1 , -1} is closed w.r.t.

• Addition A
• Multiplications B
• Subtraction C
• None of these D

(√3+√5)+√7 = √3 +(√5 +√7) property used in above is

• Commutative property of addition A
• Closure property of addition B
• Additive inverse C
• Associative property w.r.t to adition D

• 
  A
• 
  B
• 
  C
• 
  D

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

• Rule of quotient of fraction A
• Golden rule of fraction B
• Rule for product of fraction C
• Principle for equality of fraction D

A prime number can be a factor of a square only if it occurs in the square at least

• Once A
• Thirce B
• Twice C
• None of these D