1

### GATE CSE 2016 Set 2

Which one of the following grammars is free from $left$ $recursion$?
A
\eqalign{ & S\,\, \to \,\,AB \cr & A\,\, \to \,\,Aa\,\,|\,\,b \cr & B \to c \cr}
B
\eqalign{ & S\,\, \to \,\,AB\,\,|\,\,Bb\,\,|\,\,c \cr & A\,\, \to \,\,Bd\,\,|\,\,\varepsilon \cr & B \to e \cr}
C
\eqalign{ & S\,\, \to \,\,Aa\,\,|\,\,B\,\,|\,\, \cr & A\,\, \to \,\,Bd\,\,|\,\,Sc\,\,|\,\,\varepsilon \cr & B \to d \cr}
D
\eqalign{ & S\,\, \to \,\,Aa\,\,|\,\,Bb\,\,|\,\,c \cr & A\,\, \to \,\,Bd\,\,|\,\,\varepsilon \cr & B \to Ae\,\,|\,\,\varepsilon \cr}
2

### GATE CSE 2016 Set 2

A student wrote two context-free grammars G1 and G2 for generating a single $C$-like array declaration. The dimension of the array is at least one. For example, $${\mathop{\rm int}} \,\,\,\,\,\,\,a[10]\,\,[3];$$

The grammars use D as the start symbol, and use six terminal symbols int ; id [ ] num.

Grammar G1 Grammar G2
D → intL; D → intL;
L → id[E L → idE
E → num E → E[num]
E → num][E E → [num]

Which of the grammars correctly generate the declaration mentioned above?

A
Both G1 and G2
B
Only G1
C
Only G2
D
Neither G1 nor G2
3

### GATE CSE 2016 Set 2

In an Ethernet local area network, which one of the following statements is TRUE?
A
A station stops to sense the channel once it starts transmitting a frame.
B
The purpose of the jamming signal is to pad the frames that are smaller than the minimum frame size.
C
A station continues to transmit the packet even after the collision is detected.
D
The exponential backoff mechanism reduces the probability of collision on retransmissions.
4

### GATE CSE 2016 Set 2

For the IEEE 802.11 MAC protocol for wireless communication, which of the following statements is/are TRUE?

I. At least three non-overlapping channels are available for transmissions.
II. The RTS-CTS mechanism is used for collision detection.
III. Unicast frames are ACKed.

A
All I, II, and III
B
I and III only
C
II and III only
D
II only

### Paper Analysis of GATE CSE 2016 Set 2

Subject NameTotal Questions
Algorithms5
Compiler Design3
Computer Networks6
Computer Organization6
Data Structures5
Database Management System4
Digital Logic3
Discrete Mathematics11
Operating Systems3
Theory of Computation6
General Aptitude10