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This quiz will check your understanding of Lecture 5.

In accordance with the Coursera Honor Code, I (Anonymous Student) certify that the answers here are my own work.

Question 1

Which of the following are true about Bitcoin miners?

The mining difficulty is recomputed roughly every 2 weeks to keep the proof-of-work puzzle difficult

Over a 2 week period, the average time to mine a block is always 10 minutes

The target hash has become so small that the block header nonce alone isn’t generally large enough to allow miners so search enough of the hash output space to find a valid block

Bitcoin miners can more efficiently mine for blocks by specifically targeting parts of the nonce search space that have more puzzle solutions

Question 2

Which statement about Bitcoin miners is NOT true?

Mining Bitcoin on a modern CPU will yield negligible mining rewards

If the global hash rate doubles every two months, a new piece of hardware that a miner buys will find most of the blocks that it ever will mine in the first six months of operation

Many miners will consider the climate of an area when setting up mining operations because of the cost of cooling their equipment

Bitcoin miners can recoup a reasonable fraction of their initial expenses by selling their ASICs once they are done with them to other users for less computationally intense purposes

Question 3

Which of the following are assumptions made about the UPPER bound for the energy used for mining Bitcoins? (check all that apply)

Miners all pay the same for electricity

The energy efficiency of mining hardware decreases with age

Everyone mines where it is cold (cooling doesn’t consume energy)

Miners mine up to the point that all of the money they earn is used to pay for electricity

Everyone mines at the maximum claimed efficiency

Question 4

Which of the following are assumptions made about the LOWER bound for the energy used for mining Bitcoins? (check all that apply)

Miners all pay the same for electricity

The energy efficiency of mining hardware decreases with age

Everyone mines where it is cold (cooling doesn’t consume energy)

Everyone mines at the maximum claimed efficiency

Miners mine up to the point that all of the money they earn is used to pay for electricity

Question 5

Mining pools...

let members earn more rewards, on average, than they would by mining alone

evenly divide up block rewards between all members of the pool

can undermine the security of Bitcoin’s consensus algorithm, but this isn’t a problem in practice since the majority of miners aren’t part of pools

typically make all their members search for blocks with the same coinbase address (the address that receives mining rewards)

Question 6

Which of the following are true about potential mining strategies Bitcoin miners can employ? (check all that apply)

Block withholding, forking, and other attacks have been frequently carried out in practice

Miners who control more mining power have more potentially profitable strategies available

Some alternative strategies might be motivated by goals other than earning more bitcoins

In accordance with the Coursera Honor Code, I (Anonymous Student) certify that the answers here are my own work.

You cannot submit your work until you agree to the Honor Code. Thanks!

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Bitcoin and Cryptocurrency Technologies

Bitcoin and Cryptocurrency Technologiesby Arvind Narayanan

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Bitcoin and Cryptocurrency Technologies
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