ECAT Pre Engineering MCQ Test With Answer for Chapter 1 Mathematics

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

The multiplicative inverse of 0 is

• 1 A
• -1 B
• 0 C
• Does not exist 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

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

Multiplicative inverse of 0 is

• 0 A
• 1 B
• ±1 C
• Does not exist D

• 
  A
• 
  B
• 
  C
• 
  D

For each real number, there is a number which is its

• Negative A
• Possitive B
• Opposite C
• Similar D

• 
  A
• 
  B
• 
  C
• 
  D

The multiplicative inverse of -3i is

• 3i A
• -3i B
• -1/3i C
• 1/3 i D

The multiplicative inverse of 1 is

• 1 A
• -1 B
• 0 C
• Does not exist 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 = -i C
• x = 2, y = 2 D

(a +bi) -c (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

If z₁ =√-36 ,z₂ =√-25,z3 =√-16 then

• 15 A
• 15i B
• -15i C
• -15 D

Every prime number is also

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

• 
  A
• 
  B
• 
  C
• 
  D

In (x +iy) y is called as

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

In R, the additive identity is

• 0 A
• 1 B
• -1 C
• None D

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

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

If z = (x,y) , then  z ̅  =

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

• 15 A
• 15 i B
• -15 i C
• -15 D

The square root of 2i - 20i is

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

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

i³ =

• -1 A
• i B
• -i C
• 1 D

√-1 b=

• b A
• 2 B
• 2b C
• None of these D

The additive inverse of 2/3 is

• 3/2 A
• -2/3 B
• -3/2 C
• 0 D

• x A
• 
  B
• y C
• 
  D

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

• √3 i A
• √7 B
• -2-i C
• √5 D

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

• 1 A
• i B
• -1 C
• -i D

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

• 
  A
• 
  B
• 
  C
• 
  D