JAMB Computer Science Past Questions & Answers - Page 21

101.

When does the output of a NOR gate =0?

A.

whenever 0 is present at input

B.

only when all input =0

C.

whenever 1 is present at input

D.

only when all input =1

Correct answer is C

The NOR gate is a digital logic gate that implements logical NOR - it behaves according to the truth table to the right. A HIGH output (1) results if both the inputs to the gate are LOW (0); if one or both input is HIGH (1), a LOW output (0) results

102.

The number of input combination for a 4 input gate is ______

A.

9

B.

8

C.

15

D.

16

Correct answer is D

16 possible combinations
So, a 4-input AND gate has 16 possible combinations, 5 inputs would be 32 outputs, and so on.

103.

Sensitive data can be protected from prying eyes using _________

A.

File permissions

B.

File locks

C.

passwords

D.

encryption

Correct answer is A

A File permission specifies who and what can read, write, modify and access them. It therefore important as the codex explains, because without it in place, anyone or anything can access confidential files

104.

Running other software on idle computer without the knowledge of the organisation is called theft of ___________

A.

Software

B.

computer

C.

computer time

D.

use

Correct answer is C

Computer time theft is hacking into a large computer system and utilising its computing resources for a purpose not authorised by the owner of the system

105.

Which of the following software can't be categorized as an application software?

A.

DBM

B.

MS-DOS

C.

Spreadsheet

D.

word processor

Correct answer is B

MS-DOS can't be classified as an application software because, it is an operating system software. And OS are classified as system software not application software