CAT

Which one is true for an ideal decentralized solution for business management

• A centralized authority should decide the overall trust

•  Everyone should trust and cooperate with each other

• No one should trust and cooperate with each other

• No one should trust and cooperate with each other, however they should cooperate.

Bitcoin Scripting Language:

• Not Turing Complete

• Supports Cryptography

• Stack Based     

• All of the above

What is nonce?

 

• The transaction id number

• It should be Non Collision free

• The generator point used in elliptic curve cryptography

• The number miners run through to generate a correct hash

Which one of the following opcodes is needed to remove the top stack item.

• OP_POP

• OP_DEQUE

• OP_DROP

• OP_DELETE

How many Bitcoins will there ever be?

• 21 million in 2140

• 21 million in 2020

• 14 million 2015

• 23 million in 2140

 1 ether equals

 

• 1X(10 ^ 16) wei

• 1X(10 ^ 8) wei

• 1X(10 ^ 6) wei

• 1X(10 ^ 18) wei

What are smart contracts?

• define the rules and penalties around a specific agreement

• define the procedure of using wallet

• define the standard operational procedures

• define the operational procedures using nodes

What library/API is used for smart contract deployment and invocation from Dapp ?

• Contract

• web3

•   admin

• eth

Which is/are the example/s of a double-spending attack? 

• Anwesha has a total of 60 unspent bitcoins from two different transactions with an equal amount of bitcoins each. She sends the entire amount each to Arpita and Ankur from one of the transactions

• bought a bike using ‘t’ bitcoins. On delivery, the bitcoins are transferred from his wallet to the shopper ’s wallet. Simultaneously, he uses that bitcoins for another purchase Bobby

• Bibhu has 140 unspent bitcoins. He sends the entire amount each to Deepak and Tanmay

• All of the above

In which scenario is a smart contract the best solution to the problem?

  

• A restaurant manager wants to force customers to pay for their food by transferring cryptocurrency to his wallet.

• A chief engineer wants her smart watch to notify her when her partner enters their front door

• A grid company wants to automatically buy power when the price reaches a predetermined rate.

• An insurance company wants to pay out a small vendor whenever the case manager feels it is best to do so.