Electrical measurements MCQ Quiz Hub

Digital Communications MCQs set-14

Choose a topic to test your knowledge and improve your Electrical measurements skills

1. In digital communication, interaction between ______ is possible.




2. Some advantages of spread spectrum are




3. Processing gain is the ratio of message bandwidth to signal bandwidth.




4. Which is better for avoiding jamming?




5. Which is more bandwidth efficient?




6. Which is more simpler to implement?




7. Which uses orthogonal codes?




8. Which is more suitable when large number of transmitters are used?




9. CDMA rejects




10. Frequency planning is very essential in




11. CDMA uses




12. In public key cryptosystem _____ keys are used for encryption and decryption.




13. In public key cryptosystem which is kept as public?




14. In a trapdoor function, the functions are easy to go in




15. Pretty good privacy program is used for




16. PGP system uses




17. Private key algorithm is used for _____ encryption and public key algorithm is used for _____ encryption.




18. Which are called the block ciphers?




19. Which has a key length of 128 bits?




20. Which algorithm can be used to sign a message?




21. Examples of hash functions are




22. A cryptographic hash function has variable output length.




23. A set of numbers is called as super increasing if




24. Knapsack problem can be solved by




25. Merkle hellman is a symmetric cryptosystem.




26. In this Merkle Hellman method same key is used for encryption and decryption.




27. Cipher system can be solved effectively by statistically using




28. Encryption transformations are known as




29. For n input bits the number of substitution patterns are




30. In transposition, the plaintext letters are




31. The substitution of the letters are done




32. In cipher feedback method, encryption is done on




33. In stream encryption, the key sequence repeats itself.




34. In which method, key-stream is generated independently?




35. Synchronous ciphers uses




36. Public key cryptosystem uses same key for both encryption and decryption.




37. Which should be kept as a secret in public key cryptosystem?




38. Public key cryptosystem is also known as




39. Euler’s totient function is determined by




40. Pretty good privacy (PGP) security system uses




41. Public key cryptosystem is used for the encryption of




42. For digital signatures private key cryptosystem is used.




43. Data compression includes




44. PGP offers _____ block ciphers for message encryption.




45. Which block cipher has key length of 128 bits?




46. These three ciphers can operate of ______ of plaintext and cipher text.




47. The key size of DES is




48. Which operation is used in encryption using IDEA?




49. What is the key size allowed in PGP?




50. Which algorithm is used for public key encryption?