UGC NET CS 2017 Jan – III
Question 1 |
Which of the following is an interrupt according to temporal relationship with system clock ?
Maskable interrupt | |
Periodic interrupt | |
Division by zero | |
Synchronous interrupt |
Discuss it
Question 1 Explanation:
According to temporal relationship with system clock we classify interrupt in two ways:
1- Synchronous: The source of interrupt is in phase to the system clock is called synchronous interrupt. In other words interrupts which are dependent on the system clock. Example: timer service that uses the system clock.
2- Asynchronous: If the interrupts are independent or not in phase to the system clock is called asynchronous interrupt.
So, option (D) is correct.
For more information on interrupt Refer:Different types of interrupt levels
Question 2 |
Which of the following is incorrect for virtual memory?
Large programs can be written | |
More I/O is required | |
More addressable memory available | |
Faster and easy swapping of process |
Discuss it
Question 2 Explanation:
- We can write large program when we have memory extension.
- Less I/O requirement in case of virtual memory.
- More addressable memory available with virtual memory
- Faster and easy swapping of process with the help of page replacement policy in virtual memory. So, option (B) is correct. For more information on virtual memory Refer:Virtual Memory | Operating System
Question 3 |
The general configuration of the micro-programmed control unit is given below:
What are blocks B and C in the diagram respectively?

Block address register and cache memory | |
Control address register and control memory | |
Branch register and cache memory | |
Control address register and random access
memory |
Discuss it
Question 3 Explanation:
The general configuration of the micro-programmed control unit:
So, option (B) is correct.

Question 4 |
Match the following :


(1) | |
(2) | |
(3) | |
(4) |
Discuss it
Question 4 Explanation:
- In Implied Addressing Mode location of operand specified implicitly in the definition of instruction
- In Immediate Addressing Mode location of operand specified in the register.
- In Register Addressing Mode location of operand in registers which are in CPU
- In Register Indirect Addressing Mode register specifies the address of the operand
Question 5 |
In 8085 microprocessor, the digit 5 indicates that the microprocessor needs:
–5 volts, +5 volts supply | |
+5 volts supply only | |
–5 volts supply only | |
5 MHz clock |
Discuss it
Question 5 Explanation:
In 8085 microprocessor, the digit 5 indicates that the microprocessor needs +5 volts supply only.
So, option (B) is correct.
Question 6 |
In 8085, which of the following performs : load register pair immediate operation?
LDAX rp | |
LHLD addr | |
LXI rp, data | |
INX rp |
Discuss it
Question 6 Explanation:
LDAX - Load accumulator indirect( This instruction copies the contents of that memory location into the accumulator. )
LHLD - Load H and L register direct ( This instruction loads the contents of the 16- bit memory location into the H and L register pair. )
LXI - Load register pair immediate( The instruction loads 16-bit data in the register pair designated in the operand.)
INX - Increment register pair by 1.( It will increment the register value by 1.)
So, option (C) is correct.
Question 7 |
Consider following schedules involving two transactions:
S1 : r1(X); r1(Y); r2(X); r2(Y); w2(Y); w1(X)
S2 : r1(X); r2(X); r2(Y); w2(Y); r1(Y); w1(X)
Which of the following statement is true?
Both S1 and S2 are conflict serializable. | |
S1 is conflict serializable and S2 is not conflict serializable. | |
S1 is not conflict serializable and S2 is conflict serializable. | |
Both S1 and S2 are not conflict serializable. |
Discuss it
Question 7 Explanation:

Question 8 |
Which one is correct w.r.t. RDBMS ?
primary key ⊆ super key ⊆ candidate key | |
primary key ⊆ candidate key ⊆ super key | |
super key ⊆ candidate key ⊆ primary key | |
super key ⊆ primary key ⊆ candidate key |
Discuss it
Question 8 Explanation:
primary key ⊆ candidate key ⊆ super key in RDBMS
For more information Refer:DBMS | Keys in Relational Model (Candidate, Super, Primary, Alternate and Foreign)
Option (B) is correct.
Question 9 |
Let pk(R) denotes primary key of relation R. A many-to-one relationship that exists between two relations R1 and R2 can be expressed as follows :
pk(R2) → pk(R1) | |
pk(R1) → pk(R2) | |
pk(R2) → R1 ∩ R2 | |
pk(R1) → R1 ∩ R2 |
Discuss it
Question 10 |
For a database relation R(A, B, C, D) where the domains of A, B, C and D include only atomic values, only the following functional dependencies and those that can be inferred from them are :
A → C
B → D
The relation R is in _______.
First normal form but not in second normal form. | |
Both in first normal form as well as in second normal form. | |
Second normal form but not in third normal form. | |
Both in second normal form as well as in third normal form. |
Discuss it
Question 10 Explanation:
A relation is in first normal form if every attribute in that relation is single valued attribute. It is in 1NF.
{A,B} are prime attribtes and {C,D} are non-prime attribute.
A+ = {A,C}
B+ = {B,D}
{A,B}+ = {A,B,C,D} so AB is the key.
But A+ = {A,C}
B+ = {B,D} makes it partial dependency.
So, this relation is not in 2NF.
So, option (A) is correct.
There are 76 questions to complete.