Chapter 02 Groups
Chapter 02 Groups
1)  The
set N of natural numbers is closed with respect to
A)     Addition
B)      Multiplication
C)      Both A & B
D)      Subtraction
Answer:                 C
2) The
set Z of integers is closed with respect to 
A)     Addition
B)      Multiplication
C)      Subtraction
D)      A, B and C are correct
Answer:                 D
3) The set R – {0} of real numbers is closed
with respect to 
A)     Addition
B)      Multiplication
C)      Division
D)       A,B & C are correct
Answer:                 D
4) In
the set S = {0, 1} the binary operation defined is 
A)     – 
B)      + 
C)      ´
D)      ¸
Answer:                 C
5)The set S = {- 1, 1, - i, i} is a group with respect to
the binary operation
A)     ¸
B)      ´
C)      +
D)      –
Answer:                 B
6)The set S = {1, w, w2} is a group with respect to
the binary operation
A)     ´
B)      ¸
C)      +
D)      –
Answer:                 A
7) If set is a group with respect to addition then the
number of identity elements in S is 
A)     Unique
B)      Two
C)      Three
D)      None
Answer:                 A
8) If set S is a group with respect to addition then each
element of S has _____ inverse. 
A)     Unique
B)      Two
C)      Three
D)      None
Answer:                 A
9)R
– {0} is a group w.r.t the binary operation
A)     +
B)      ´
C)      ¸
D)      –
Answer:                 B
10)Q
– {0} is a group w.r.t the binary operation
A)     +
B)      ´
C)      ¸
D)      –
Answer:                 B
11) R
is a group w.r.t the binary operation.
A)     +
B)      ´
C)      ¸
D)      –
Answer:                 A
12)Q
is a group w.r.t the binary operation.
A)     +
B)      ´
C)      ¸
D)      –
Answer:                 A
13) S
= {1, - 1} is a group w.r.t the binary operation.
A)     + 
B)      ´
C)      -
D)      none of these
Answer:                 B
14)S
= {0} is a trivial group under 
A)     +
B)      ´
C)      ¸
D)      –
Answer:                 A
15) S
= {1} is trivial group under 
A)     +
B)      ´
C)      –
D)      division
Answer:                 B
16) A non empty set S which is closed with a binary operation
‘*’ is called group if
A)     The binary operation is
associative
B)      There exists identity
element with respect to the binary operation. 
C)      There exist a unique inverse
of each element of S with respect to the binary operation. 
D)      All A, B & C hold. 
Answer:                 D
 17)In a proposition  if   p→
q then q  → p is called
A)      inverse of  p→ q
B)       converse of  p→
q
C)       contrapasitive 
p→ q
D)      none
Ans: B
18)Truth table containing all false values
is called
A)  Tautology
B)
Selfcontridiction 
C)
Equivallent
D)
None 
Ans: B
19)Truth table containing all true values
is called
A)  Tautology
B)
Selfcontridiction 
C)
Equivallent
D)
None 
Ans: A
 20) In a proposition
if p→ q then contrapasitive of this proposition is denoted by
A)          
q  → p
B)           
~ q  → p
C)           
~ q  →  ~ p 
D)           
None
Ans: C
 21) In a proposition
if p→ q then inverse of this proposition is denoted by 
A)          
q  → p
B)           
~ q  → p
C)           
~ p  →  ~ q 
D)           
None
Ans : C
 22) In a proposition
if p→ q then converse of this proposition is denoted by
A)          
q  → p
B)           
~ q  → p
C)           
~ q  →  ~ p 
D)           
None
Ans: A