MCQOPTIONS
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MCQOPTIONS
This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A linear Hamming code is used to map 4-bit messages to 7-bit code words. The encoder mapping is linear. If the message 0001 is mapped to the code word 0000111, and the message 0011 is mapped to the code word 1100110, then the message 0010 is mapped to |
| A. | 0010011 |
| B. | 1100001 |
| C. | 1111000 |
| D. | 1111111 |
| Answer» C. 1111000 | |
| 2. |
CDMA is: |
| A. | Direct Sequence Spread Spectrum system |
| B. | Frequency Sharing system |
| C. | Tie hopping system |
| D. | Time sharing system |
| Answer» B. Frequency Sharing system | |
| 3. |
GPRS stands for |
| A. | General Packet Radio Service |
| B. | Global Positioning Radio Service |
| C. | Geological Packet Radio Service |
| D. | Geological Positioning Radio Service |
| Answer» B. Global Positioning Radio Service | |
| 4. |
Identify the advantages of 2G from below |
| A. | Calling was included |
| B. | The increase of overhead in signaling paved the way for capacity enhancement. |
| C. | Higher bit rate voice coding enabled more users to get the services simultaneously. |
| D. | New services such as SMS were included |
| Answer» E. | |
| 5. |
In a DTMF (Dual-tone multi-frequency) Phone, digits are represented by: |
| A. | Orthogonal frequencies |
| B. | Orthogonal phases |
| C. | Orthogonal codes |
| D. | Orthogonal pulses |
| Answer» B. Orthogonal phases | |
| 6. |
A signal m1(t) is band limited to 3.6 kHz and the three other signals m2(t), m3(t) and m4(t) are band limited to 1.2 kHz each, and these signals are transmitted by means of TDM. Then, what will be the transmission bandwidth of channel. |
| A. | 7.2 KHz |
| B. | 14.4 KHz |
| C. | 3.6 KHz |
| D. | 2.4 KHz |
| Answer» B. 14.4 KHz | |
| 7. |
All CDMA based technologies 2G and 3G have |
| A. | Soft handover |
| B. | Hard handover |
| C. | Blind handover |
| D. | Soft and Hard handover |
| Answer» B. Hard handover | |
| 8. |
If one of the code words of a Hamming (7, 4) code is 0001011, which of the following cannot be the valid codeword in the same group? |
| A. | 0011101 |
| B. | 0101100 |
| C. | 0011010 |
| D. | 1110100 |
| Answer» D. 1110100 | |
| 9. |
In a CDMA system, there are 32 simultaneous users in the system. Find the number of different codes used. |
| A. | 48 |
| B. | 36 |
| C. | 32 |
| D. | 52 |
| Answer» D. 52 | |
| 10. |
Blocked calls may be handled in one of the two ways. First blocked calls can be put in a queue awaiting a free channel. This is termed as |
| A. | Lost Calls Cleared (LCQ) |
| B. | Lost Calls Delayed (LCD) |
| C. | Lost Calls Held (LCH) |
| D. | Lost Calls Handoff |
| Answer» C. Lost Calls Held (LCH) | |
| 11. |
A combination of direct sequence and frequency hopping is called |
| A. | Direct sequence hopping |
| B. | Hybrid direct frequency hopping |
| C. | Direct sequence frequency hopping |
| D. | Hybrid direct sequence frequency hopping |
| Answer» E. | |
| 12. |
A seven-bit Hamming code is received as 1111101. What is the correct code? |
| A. | 1101111 |
| B. | 1011111 |
| C. | 1111111 |
| D. | 1111011 |
| Answer» D. 1111011 | |
| 13. |
Hamming codes are used for |
| A. | Burst error correction |
| B. | Signal error correction |
| C. | Both (a) and (b) |
| D. | None |
| Answer» D. None | |
| 14. |
A digital transmission system uses a (7, 4) systematic linear Hamming code for transmitting data over a noisy channel. If three of the message-codeword pairs in this code (mi ; ci), where ci is the codeword corresponding to the ith message mi, are known to be (1 1 0 0 ; 0 1 0 1 1 0 0), (1 1 1 0 ; 0 0 1 1 1 1 0) and (0 1 1 0 ; 1 0 0 0 1 1 0), then which of the following is a valid codeword in this code? |
| A. | 1 0 1 1 0 1 0 |
| B. | 0 1 1 0 1 0 0 |
| C. | 0 0 0 1 0 1 1 |
| D. | 1 1 0 1 0 0 1 |
| Answer» D. 1 1 0 1 0 0 1 | |
| 15. |
In microwave communication systems, sometimes, the same frequency is used by the separation of signals through vertical and horizontal polarization. This technique is generally called |
| A. | Steady frequency multiplexing |
| B. | Variable frequency modulation technique |
| C. | Frequency reconditioning technique |
| D. | Frequency re-uses technique |
| Answer» E. | |
| 16. |
Assertion A): If the frequencies are in the microwave range, H, Y, and Z parameters can not be measured.Reason R): Short and open circuits are difficult to achieve over a broad band of frequencies and active devices such as power transistors and tunnel diodes, frequently will not have stability for a short or open circuit.Choose the correct answer: |
| A. | Both A) and R) are true and R) is the correct explanation of A) |
| B. | Both A) and R) are true, but R) is not the correct explanation of A) |
| C. | is true, but R) is false |
| D. | is false, but R) is true |
| Answer» C. is true, but R) is false | |
| 17. |
Hamming code is |
| A. | An error detection code system |
| B. | An error correction code system |
| C. | A programme conversion code system |
| D. | None of the above |
| Answer» C. A programme conversion code system | |
| 18. |
Each earth station's transmission is encoded with a unique binary word called |
| A. | Station code |
| B. | Chip code |
| C. | Access code |
| D. | Gold code |
| Answer» C. Access code | |