Is the access time to any RAM address the same and unchanged?

Question

Processors

Please help me to deal with the questions, I searched on the Internet, everywhere they write about the wrong thing.
3) The access time to any RAM address is the same and invariably
False
True
Explain this point, please, why the access time should be different at all, because the RAM has the same memory cells.
4) All computers execute program commands sequentially.
False
True
As far as I understand it, all commands are translated into binary code understandable by the computer and are executed in turn, sequentially
5) If two programs are simultaneously executed on two cores of the same processor, then the resulting execution time will be the same.
False
Truth
It seems to me a lie, since the program can be of different length / complexity and will be completed in different times.

Answer 1

3) https://stackoverflow.com/questions/51813009/why-d...
4) depending on what the teacher wants to hear, there are processors with parallel execution
5) yes, other things being equal, the
questions are all logical, not physical

Answer 2

3) no, modern RAM contains "banks", which are already subdivided into rows and columns, switching between which takes time. therefore, reading the address is very close to the previous readable one - a little faster than the address at the other end of the RAM
4) is long gone, modern processors have microcode for subdividing commands into lower-level ones, branch predictor, caching, pipeline execution. logically they are executed sequentially. really - the processor can easily execute three consecutive commands simultaneously, if it considers that their result does not depend on the order of execution.
5) and again no, it depends on the state of the pipeline, the predictor and a bunch of other conditions of the execution cores. for example, the command to read the memory address, depending on whether we hit the cache or not, can be executed 10/100/1000 times slower on another core
, however, if your textbook with questions from the 70s, the answers may be different

Answer 3

3) The access time to any RAM address is the same and invariably
False
True
Explain this point, please, why the access time should be different at all, because the RAM has the same memory cells.

It depends on many parameters. In some configurations yes, in others no.
Read about NUMA about memory banks, about the memory controller.

4) All computers execute program commands sequentially.
False
True
As far as I understand it, all commands are translated into binary code understandable to the computer and are executed in turn, sequentially

It all depends on the architecture.
ARM execute more or less sequentially
x86 x64 contain prefetch blocks and execute both branches and discard the unnecessary

5) If two programs are simultaneously executed on two cores of the same processor, then the resulting execution time will be the same.
False
True
It seems false to me, because the program can be of different length/complexity and will be executed in different time.

Not always. Firstly, the OS scheduler decides, secondly, the priority of programs, and thirdly, the kernel can be throttled or boosted.