Page 152 - Viva ICSE Computer Studies 7 : E-book

Choose the correct answer. Award +1 for every correct answer and deduct 0.25 for every incorrect
answer. Calculate your score and write it in the space provided at the end of this section.

1. According to decimal number system, in number 642, 6 is _____________ and 2 is
_______________.
(a) most signifi cant digit, least signifi cant digit

(b) least signifi cant digit, most signifi cant digit
(c) greater, smaller

(d) smaller, greater

2. According to the binary number system, which of the following is correct for number ‘5’?
(a) 011 (b) 101

(c) 110 (d) 010
10
3. (25) = (?) 2
(a) 11011 (b) 10011
(c) 11001 (d) 11101

4. Which of the following is not a feature of Backdoor virus?

(a) It is a coded program.
(b) It masks the existence of virus or malware by making it appear to be friendly.

(c) It steals information from the computer.
(d) It makes the fi le unreadable.

5. Maya’s computer has started showing the following symptoms.
• Disk’s space is fi lled up by copying itself endless times.

• Speed of the computer is reduced.
• Unexpected error messages display on the screen.
• System shuts down automatically.

Choose the correct option as a solution to her problem.

(a) Her computer is infected with a virus. She needs to format the system and install antivirus
software.
(b) Her computer is overloaded. She should format the system.
(c) She needs to buy a new system.

(d) She should stop using the system for some time.

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