adplus-dvertising
41. physical layer provides
a. mechanical specifications of electrical connectors and cables
b. electrical specification of transmission line signal level
c. specification for IR over optical fiber
d. all of the mentioned
Answer: (d). all of the mentioned

42. In asynchronous serial communication the physical layer provides
a. start and stop signalling
b. flow control
c. both (a) and (b)
d. none of the mentioned
Answer: (c).both (a) and (b)

43. The physical layer is responsible for
a. line coding
b. channel coding
c. modulation
d. all of the mentioned
Answer: (d).all of the mentioned

44. A single channel is shared by multiple signals by
a. digital modulation
b. multiplexing
c. analog modulation
d. none of the mentioned
Answer: (b).multiplexing

45. Baud means?
a. The number of bits transmitted per unit time
b. The number of byted transmitted per unit time
c. The rate at which the signal changes
d. None of above
Answer: (c).The rate at which the signal changes

46. Which of the following devices takes data sent from one network device and forwards it to all devices on the network regardless of the intended recipient?
a. DNS Server
b. Switch
c. Hub
d. Gateway
Answer: (c).Hub

47. Which of the following devices takes data sent from one network device and forwards it to the destination node based on MAC address?
a. Hub
b. Switch
c. Gateway
d. Modem
Answer: (b).Switch

48. which of the following devices is used to connect different network segments and manage the traffic between them?
a. Bridge
b. Hub
c. Gateway
d. Repeater
Answer: (a).Bridge

49. Unipolar, bipolar, and polar encoding are types of _______ encoding.
a. line
b. block
c. NRZ
d. Manchester
Answer: (a).line

50. _______ encoding has a transition at the middle of each bit.
a. RZ
b. Manchester
c. Differential Manchester
d. All the above
Answer: (d).All the above

Page 5 of 24