ECAT Pre General Science MCQ Test With Answer for Mathematics Chapter 1

The multiplicative inverse ofx^(-1) is

• x A
• a-2 B
• 0 C
• 1 D

Multiplicative inverse of 0 is

• 0 A
• 1 B
• ±1 C
• Does not exist D

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

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

• N A
• r B
• 2r C
• π D

• 1 A
• -i B
• i C
• 0 D

If z=(x,y) then z has no multiplicative inverse when

• x ≠ 0, y = 0 A
• x = 0, y = 0 B
• x = 0, y ≠ 0 C
• None of these D

• Additive property in R A
• Multiplication property in R B
• Cancellation property in R C
• Distribution property in R 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

• 
  A
• 
  B
• 
  C
• 
  D

• z is purely imaginary A
• a is any complex number B
• z is real C
• None of these D

• 
  A
• 
  B
• 
  C
• 
  D
• 
  E

The set {0,-1} hold closure property under

• Addition A
• Both a & c B
• Multiplication C
• None of these D

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

• 
  A
• 
  B
• 
  C
• 
  D

3/2 is

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

Gooch crucible is made of :

• Brass. A
• Porcelain. B
• Bronze. C
• Gold. D

For any real numbers x,y,xy=o ⇒

• x ≠ 0 ∧ y ≠ 0 A
• x = 0 ∨ y = 0 B
• x = 0 C
• y = 0 D

• 
  A
• 
  B
• 
  C
• 
  D

What is the conjugate of -7 -2i ?

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

√25 is a number

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

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

• 
  A
• 
  B
• 
  C
• 
  D

• 
  
  
  A
• 
  B
• 
  C
• 
  D

(7,9) +(3,-5) =

• (4,4) A
• (10,4) B
• (9,-5) C
• (7,3) D

The set of rationals numbers between 0 and I is

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

0.25 is ______

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

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

• 
  A
• 
  B
• 
  C
• None of these D

(a-1)-1 =

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

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

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