Rajasthan Adming Services (RAS)/RTS Exam Computer Science, Computer Engineering Sample Paper 3: Question for Computer Science and Computer Engineering Subject from Networking and Operating System(OS). You Might like RAS Pre Papers Computer Science and Engineering For more updates on RAS Exam Follow us on FACEBOOK OR GOOGLE+ . 
1.The Method of Communication in which transmission takes place in both directions but only in one direction at a time is called:
A. Simplex
B. Four wire circuit
C. Full Duplex
D. Half-Duplex
Ans: D
2. Error detection at Data link level is achieved by:
A. Bit Stuffing
B. Cyclic redundancy code
C. Hamming codes
D. Equalization
Ans: B
3. Which of the following is a wrong example of a network layer:
A. IP-ARPANET
B. X.25 packet level protocol(PLP)-ISO
C. X.25 level-2 ISO
D. Source routing and domain naming using USENET
Ans: C
4. baud means:
A. No. of bits transmitted per second
B. No. of Bytes transmitted per second
C. The rate at which signal changes
D. None of the above
Ans: C
5. The start and Stop bits are used in Serial Communication for:
A. Error detection
B. Error correction
C. Synchronization
D. Slowing down communication
Ans:C
6. Un-modulated singnal coming from a transmitter is known as:
A. Carrier Signal
B. Baseband signal
C. Primary signal
D. None of the above
Ans: B
7. Manchester code is a:
A. Bi-Polar code
B. Non return to zero code
C. Polar code
D. Non of above
Ans: B,C
Rasexam.com Tips:  Its Non-return to zero and is Unipolar as shown in below diagram.












8. Which of the following is Non-Polling system:
A. TDMA
B. Stop and wait
C. Xon/Xoff
D. Continuous ARQ
Ans: C,D
9. How may characters per second(7Bits+1parity) can be transmitted over a 2400 bps line if the transfer is synchroous (1Start and 1 Stop)
A. 300
B. 240
C. 250
D. 275
Ans: B
RasExam.com Tips: In synchronous transfer Start and stop bits are not needed so its 2400/8=300.
10. The hamming distance between 001111 AND 010011 is:
A. 1
B. 2
C. 3
D. 4
Ans: C
11. HDLC is:
A. Character oriented protocol
B. Bit oriented protocol
C. Code depended
D. Non of above
Ans: B
12. BSC is a:
A. Character oriented protocol
B. Bit oriented protocol
C. Full duplex protocol
D. Non of above
Ans: A
13.  Which of the following network uses dynamic routing:
A. TYMNET
B. ARPANET
C. IBM's SNA
D. None of above
Ans: B
14. End-to-end connectivity is provided from host to host in:
A. Network layer
B. Transport Layer
C. Session layer
D. Both Network and data link layer
Ans: B
15. If the Bit string 0111101111101111110 is subject to bit stuffing for the flag starting 0111110 the output string is:
A. 01111011111011111010
B. 0111101111101111100
C. 0111101111101111010
D. 01111011111011111001
Ans: A
16. Which of the following is not a standard RS-232C Signal
A. RTS
B. CTS
C. DSR
D. VDR
Ans: D
17. The frequency range at which the Landline Phones Coaxial cable is used is:
A. 10*6 to 10*8 Mhz
B. 10*10 to 10*11 Mhz
A. 10*3 to 10*4 Mhz 
A. 10*14 to 10*15 Mhz
Ans: A
18. Which one of the following uses UDP as the transport Protocol
A. HTTP
B. Telnet
C. DNS
D. SMTP
Ans: C
19. The maximum data rate of a noiseless 3KHz Binary channel is:
A. 3000 bps
B. 6000 bps
C. 1500 bps
d. None of above
Ans: B
20. Which one of the following is not a Client-Server Application:
A. Internet chat
B. Web browsing
C. Email
D. Ping
Ans: D