Computer & IT

note!Answer: A) semiconductor memory
Semiconductor memory such as RAM loses its contents when power is removed, so it is volatile.

note!Answer: A) allow the computer to store data electronically
RAM chips are electronic primary memory that temporarily stores data for the CPU. They are volatile, so they do not store data indefinitely.

note!Answer: D) electrically erasable
EEPROM stands for Electrically Erasable Programmable Read-Only Memory.

note!Answer: C) duplex
Duplex (full duplex) communication allows simultaneous transmission in both directions. Simplex is one way only, and half duplex allows both ways but not at the same time.

note!Answer: B) converting digital signals to analog singals
Modulation converts digital data into an analog signal for transmission over analog media. The reverse process is demodulation.

note!Answer: B) star network
In a star network, every node connects to a central hub or computer, and all data passes through it.

note!Answer: D) All of the above
Traditional file systems suffer from data redundancy, difficulty in updating, and strong program-data dependence.

note!Answer: B) transaction file
A transaction file (or log) records all transactions that changed database contents over a period, which supports recovery and auditing.

note!Answer: A) record
In a database hierarchy, related fields combine to form a record, and related records form a file.

note!Answer: B) rows and columns
In a relational database, a table is made up of rows (records) and columns (fields).

note!Answer: B) access path
An index gives a fast access path to records in a file based on a key value.

note!Answer: D) All of the above
The database approach reduces redundancy, allows related data to be linked, and provides better security controls.

note!Answer: B) data inconsistency
When a value is updated in some files but not in others, the same data item has conflicting values, which is data inconsistency.

note!Answer: A) data redundancy
Storing the same field multiple times is data redundancy, which wastes space and can cause inconsistency.

note!Answer: C) software available on hardware
Firmware is software permanently stored in a hardware device, such as ROM or flash memory.

note!Answer: B) 1 1/2
Sign 0 is positive. Exponent 101 is 5, minus excess 4 gives 1. Mantissa 1100 is .1100 = 3/4, and 3/4 × 2^1 = 1 1/2.

note!Answer: D) 6 1/4
6 1/4 = 110.01 in binary, which needs 5 mantissa bits after normalizing. The format has only 4 mantissa bits, so it cannot be stored exactly.

note!Answer: C) 00101000
All options are positive, so the smallest has the most negative exponent. 00101000 has exponent 010 = 2, which is -2, giving 0.5 × 2^-2 = 0.125, the smallest of the four.

note!Answer: A) Main memory
Main memory (RAM) gives direct access to any address in nearly the same time. Disks and optical media need mechanical movement to reach data.

note!Answer: D) Flash drives
Flash drives use solid-state memory with no moving parts. Tapes, disks and DVDs all rely on physically moving media or heads.